To make a server, you will need SteamCMD, preferably from a trustable source.
Now, set up your server, you will see how if you search a video.

When making a server, you should first decide which gamemode, then which map, how its gonna be played, then the addons.

When choosing a gamemode for your server, if you want a lot of players, choose either *cough cough* the cursed DarkRP or Trouble in Abuse town (TTT)

Now if you actually want a good and fun server, CHOOSE SOMETHING ELSE

Here are some good gamemodes:
Murder
Sandbox but only fun when the other players are your friends
bomberman?
i honestly dont know for this one
Literally anything that isnt ttt or darkrp

Now, when you choose a map, dont ♥♥♥♥♥♥♥ choose rp_downtown or its million copies of it.
For sandbox you should choose either construct, flatgrass or mobenix.
For Murder you can choose any map that is large and isnt flat (Construct, peaches castle are examples)
For darkrp you should close your server forever
For some of more complex gamemodes however, there will be a few maps designed for that specific gamemode, so choose those, you can see which is which map by their prefix such as gm (Sandbox) zm (Zombies) and cs (Counter-Strike (Not a gamemode but still))

here are some quick tips before we get into the main thing
1. dont have 8 year olds as admin
2. dont add buyable admin
3. serious admins do their job better but are more annoying for the players

When you have admins, its better to not hire kids as they are bad at being admins, ALSO PAY YOUR DAMN ADMINS IF THEY DO A GOOD JOB
Do not add buyable admin as its easily abusable, and dont add admin things in your vip ♥♥♥♥ either, because its glorified buyable admin then.
More serious admins are better then admins that like jokes n ♥♥♥♥ but they will be more annoying to normal players.
Make sure the admins are actually active, and have at least 2 admins that can moderate the server when the other is asleep
pay your admins or they will stop working for you

and please for the love of god dont have admins that ban you for breathing

dont have buyable admin or buyable addons and dont lock 103291030912 addons behind a bad vip paywall
enough said.

Dont have 10 million addons, and dont ♥♥♥♥♥♥♥ have vapes or overused weapon addons
like seriously can you guys be more original with the addons? add something thats actually good like ragmod or scars for ♥♥♥♥ sake

and if you do have 50 million addons, then dont have blaring music in the background when players are downloading your 100 million addons, but that may be prevented if you didnt have 200 million addons in the first place.

just dont have 500 million addons

Add basic rules like:
Dont be a douchebag
Dont propkill
Dont propspam
Dont hack

The basic things and the more advanced ones are fine.
But dont add stupid ones like "Dont kill the admins" or "Dont breathe"

just dont.

Dont be like the 10 million darkrps there are and have something original, something players will actually enjoy, something that doesnt limit their minds but still limits on what they can do so they dont break anything important for the server

For example, blacklist props that people can spam and crash the server or you can make it only 1 per person

tl;dr: dont be a darkrp server