If you're looking for the bread and butter of the game, whelp, this is the knife you apply it all with. Speaking of knife, it does 80 damage while ignoring most skills of the game. It also sets cars on fire. Actually hitting someone with it has gotten much harder, mostly for bashing NPCs.

Pistols have a good running speed and switch faster than other weapons.
USP; Everyone spawns with one, very accurate. Should replace quickly.
Flare Gun; Slow projectile, high damage per shot. Bonus against vehicles.
Desert Eagle; Massive recoil, good damage and high dps. Great for killing civs.
Tasers; No recoil, high dps, perks of a pistol. A great Super weapon for try hards.

aka DPS, have the perks of a pistol and much more fire rate.
Uzi; Solid gun, only suffers at range.
MP5; Improved Uzi. Really, that's it.
Nailgun; Some fully automatic sci-fi smg that fires, wall bouncing bullets, at an obscene rate.
Flamethrower; Not really an smg, but kind of same role. Ignores defensive skills like Force Field, great AOE for Squads.

Ideal for point-blank face melting. A good buy when you're tired of dealing with people using SMGs.
M3 Super; Hide and Seek Peekabo in gun form. 2 Shots loaded. Best Weapon.
Spas; Automatic Shotgun. If using the M3 is too hard.
Blastcannon; Explosive Ammo, can Rocket Jump and climb walls. Charge Shots optional.

Assault rifles. It's like a sniper rifle and an smg had a baby that neither wanted.
AK47; High RPM acts like an SMG. But you can tap fire for long range.
M4A1; Burst fire makes it a sniper shotgun. Extremely deadly when accurate.
Seek Rifle; 3 bullets per shot, that automatically steer towards enemies. Good for drive bys.

Holding one slows you down significantly, also they have massive clip sizes and extra damage to vehicles.
M249 SAW; 100 rounds of heavy metal freedom.
M60; Best DPS on Round 2.
Minigun; Fires all barrels at the same time, 10 times a second. Great against vehicles.

The Scope mechanic is you can move the camera based on your cursor position.
Ruger; Mobile long rifle with a good rof, shoots quickly and accurately while moving.
Barret; Long Distance M3 Super. Pair with every range bonus and become the nightmare.
Photon Beam; Shoots a laser that melts anyone standing inside it.

Hold 3 nades or bazookas. Default is F to use them.
Grenade; Can bounce off walls and lob over terrain. Explodes on vehicle contact.
Molotov; Leaves a fire in the blast radius, good area denial and damage to vehicles.
Bazooka; The Homing Armor-piercing rocket does massive damage to vehicles, and less to people. Instant firing makes a good sidearm.
Flashbang; Blinds people. Little damage, can kill police and civs with its in-built multiplier.

Crits randomly trigger when shooting something. Big red lights surround you, screams and stuff. During this you fire without spending ammo, and bullets deal double damage.

In between games, there are 4 Classes you can pick from that adjust how the game works for you.

The most intuitive playstyle. Your 'dodge roll' goes farther, you can continue shooting during, and you just move faster in general. As well, you get extra healing from killing any enemy. Fits well with pretty much anything.

Deal extra damage the further away the enemy is. And all your guns shoot slightly further as well. (5m, about the length of 2 player hitboxes side by side.)
The Black Market trait means you can find a Barret to buy in the first Round, which is perfect for this. M4A1 is also great.
And you have double grenades, for when the first shot scares them into cover.

When below half health, you take less damage and shoot faster. Great against miniguns, smgs, shotguns. Even machineguns suffer. But be weary of Snipers and Casters... They mostly ignore this damage reduction by damaging in bursts. And you bleed medkits, which you can pick up like some lego monster and put yourself back together.

My personal favorite. You get +30 hp whenever you use an ability, which is fine, and becomes great once your abilities have a cooldown of about 8 seconds. You also start the game with a higher level, and get more rewards from killing people.

Hold ALT in-game and mouse to the top of the screen. You'll get a drop down of 2 skills to pick from your 'draft pool'. Periodically it will guarantee a Legendary or Rare for everyone. Aside from legendary, you can spend $1k to reroll the choices. Should do it once in a while if something really bad comes up (for you) comes up.
Can also change teams / duos partner in the top left if it's round 1.

The draft tries to avoids any skills that were in the last 2 options. And if you skip a Rare pool, it will give you a higher chance to see a rare until you pick one. (Something like 3x as likely.)

Each skill can have 7 points into it, increasing it's effectiveness.

In the Unlocks menu, you can see the exact details of what every skill does, and it is organized into one of 6 categories. Also, there are Active and Passive skills. Actives are the big deal, you can only have 3 of them and at level 7 act like ultimate abilities that can take off half or more of someone's health bar, or stop it from happening to you.

Now I will provide a short description of all the active skills, so that you can get an idea of what you want to look for instead of having to piece together all the numbers of the descriptions.

Cluster Bomb. Juggle some free grenades, dropping them randomly at any nearby enemy.

Firestorm. A confusing Fireball that has a trail of smaller versions, doesn't set anyone on fire, and does more damage the further away they land.

Blade Fury. Juggle a lot of shurikens, melting anyone standing on top of you. Trigger again to shotgun them all around you.

Venom Shot. Fire a long range homing spread of 3 poison darts that will sap away, reasonably about a third of your hp.

Radiate. Basically an airstrike Molotov, always has the same landing delay regardless of distance. Area Denial.

Energy Vortex, a big brrrrrrrr gray circle that slows enemies down by touching it, and gives you their health slowly.

Smoke Bomb. Creates a smoke screen that heals and conceals you. Won't hide you if you're shooting a gun, though.

Hypnotic Army. Rockerboy time, grab civilians to fight for you. PING by holding ALT and clicking, will tell them to go there. Or if on yourself then to follow you again. They should ride vehicles with you.

Invisibility, it does exist. But it fails to work if you stand next to someone. 10m, so like 5 player models.

Self Repair. Self explanatory. The heal has a slight delay.

Shockwave. A 45 degree cone that pauses every bullet it touches, and heals you for it. Bullets will still do damage, and resume flying shortly after. Also affects some skills, like Firestorm and Venom Shot.

Backtrack. Set a save state of your health and location, and next cast uses that save state.

Force Field. The Reinhardt ability. Will reflect bullets shot at it.

Mirror Image. If you ever wonder why that kill just poofed with no rewards, it was an illusion. Illusions can hurt.

Bullet Time. Gives you a grazing aura that slows down every bullet in it, including your own, but gives yours the benefit of auto aiming toward enemies after they leave the aura.

Frenzy. Shoot and move faster for 3 seconds. Simple.

Spike Trap. Grenades out a row of spikes that damage anyone, particularly vehicles, passing through. Possible to climb a box and jump over. If aimed directly on yourself, makes a circle.

Phase Drifting. Lets you ice skate on concrete. Great for ignoring the movement penalty of machine guns.

Toxic Blood, if you're confused why suddenly a big blood boil appeared and is doing damage to you, this is that skill.

X-ray Vision. In-game wallhack does exist.

Skill Shots, it's not dandruff. If someone has little white orbs flying around them, then their actives will hurt much more. Flying Dagger too.

Flying Dagger. Your knife becomes a ranged attack. Maxed, it becomes a sniper rifle.

Bouncing Bullets. Your bullets will ricochet off walls and do additional damage.

There are a few more interesting passives, like Poison Trail, but mostly obvious enough or simply give stat increases, like more health, damage, range, etc.

There are some combos that you just instantly die to. Such as a super stacked Sniper Barret with bouncing bullets hitting you twice like a boomerang. Or someone with a fully stacked blade fury and detonating on top of you. Or that Manic Mechanic with the perfect timing on running you over.

Vehicles are weird, they take bonus damage from some weapons and abilities, but also regenerate health much like a player does if damage is not taken after a while. You can run people over if you're fast enough.

Police Patroller, Pretty fast, no health, but you'll see them everywhere. You'll know it when you see or hear it.

Loafer is the cheapest vehicle (you can buy), it is a little safer than a Patroller but has much less speed.

Buggie is a nice compact car. It's small and quick, with a bit more speed than a loafer.

Gallant muscle car is efficient personal transport. Twice the health of a Patroller and will survive a bazooka hit.

Pickup Truck features a 360 seat in the back but is slower than most. Great for duos.

Radar Trucks reveal enemies in a 50m radius around it. Does not have to be occupied to work. Very slow.

Camper van is basically a bunker on wheels. They're also too tall to jump over and can fit 6 people inside.

Roadster is an extremely fast hair dryer on wheels. Tends to roadkill when you aren't even trying to.

Torpedo is a timebomb with wheels. Click once to arm/disarm the bomb. Won't kill the driver if he so happens to suicide bomb with it. Good at nuking other vehicles.

Flatbed features THREE 360 seats. Very impressive if fully crewed.

Hornet jeeps go fast, have armor, and SEEKER MISSILES, with similair armor piercing as a bazooka.

Cyber Truck is a very rare vehicle spawn that has two flamethrowers mounted on the front. Enjoy.

Probably the last thing anyone learns about if left to their own. Chemicals carry two effects, one active at all times, and another you stand on after placing down. Using C will bring up a wheel of which chemical to place. Chemicals last for 20 minutes, and standing on an enemies' chemical for 3 seconds will make it yours.

Each one is consistently priced at $6k and refill a 'placement' every minute.

Warp field was made by geniuses to be used carelessly. Standing on one you hold ALT and click on an arrow--possible arrows are captured points and other warp fields--to teleport there. Has no range limit. Holding one makes shifts restore 30% faster.

Sonar Cells reveals everyone on the map when standing inside. Reccomend holding ALT to full size the minimap. Holding one makes your view slightly bigger.

Goo Traps make a funny noise when someone else steps on it, and is slowed to 60%. Holding one lets you jump higher, so roofs become a lot easier to run on. Perfect sniper companion.

Health Stimulant Simple. Heal 10hp/s for 5s after touching it. Holding one lets you hold 15 more health.

Fission Mine goes beep-beep-boom. 2 seconds after it triggers, kills anything standing on it, and damages anything around it. Holding one gives you a grenade every 40 seconds. This grenade is a copy of the grenade type you're currently holding.