Okay, so I'm guessing you're a Hololive fan correct?
So at least you know how to play games?
If you said no then that's a skill issue, luckily this guide is here to "guide" you.
If you said yes then good for you.
So now for the step-by-step guide to show you what to do.

Step 1: Wait for the logos to be finished. (You can hit a key if you want to skip them)
Step 2: Do you see the text saying "Press any key to continue"? Well you're now in the title screen, and pressing any key in your keyboard will send you to the main menu.
Step 3: Once you're in the main menu, you will see 6 buttons which you can select using the WASD keys, rather than the arrow keys. This is a quirky thing you gonna have to get used to after playing Holocure, which uses the arrow keys.
Step 4: Select "Training"
Step 5: You will see 3 options: Training Room, Tutorial, and Command list. Select "Tutorial"
Step 6: You will now be in a menu consisting of many options. Just choose "Basic Movement" and move on.
Step 7: Since this is a guide and I'm a crazy person I'm just gonna put the ENTIRE TUTORIAL on the next chapter.

Before you get to beat hololive members up. You must know the basics to at least prevent from getting your *** kicked on Very Easy diffuculty.

Controls
Movement:
W - Jump
A - Move backwards (Block)
S - Crouch
D - Move forward
Space - Use Item (Only used in Virtual Frontier)
J - Light attack
K - Medium attack
L - Hard attack
I - Special (Used for special moves)
O - Grab
Y - Collab (Use this to summon your partner aka Collab character)
P - Burst (Used to escape being rekt)
Controller: (Later)

General Commands:
Dash forward - Hit the Move Forward button 2 times in quick succession (and hold for run)
Dash backward - Hit the Move Backward button 2 times in quick succession
Crouch attacks - Crouch + Light, Medium, Heavy attack
Overhead attacks (To hit someone who is crouching) - Medium + Heavy attack at the same time
Sweep - Hold Crouch + Left or Right and then hit the Heavy attack button
Quick Rise (Get up faster after being launched) - Hold the direction you are being launched at (e.g Left or Right)
Air Tech (Get a quick recovery in the air) - Hold the opposite direction you are being launched at in the air
Grab escape - Hit the Grab button as you are about to be thrown
Special moves - Special button + Left, Right, Down keys or Jump + Special button
Motion inputs - Down + Forward in quick succession + Light, Medium
Super attacks - Down + Either the Forward or Backward buttons in quick succession + Heavy attack
Super Star Attack - Down + Forward in quick succession + Special button

Basic Combos:
Basic Cancel Combo: Light + Medium + Heavy attack
Same button Cancel: Normal attack + Any movement button + The same attack in quick succession.
Normal to Special: Any Normal attack + Special Attack

Oof. That's a lot to read. I'm sure I can explain everything in less words, but I have no idea what to change.
Next up: Playing the game.

Okay you just read a bunch of stuff that you need to remember while you're playing this game.
So now, we can actually start fighting.

Step 1: Go back to the main menu. You can do this by hitting the "esc" button on your keyboard.
Step 2: When it prompts you to "Go Back" just hit enter to select yes.
Step 3: Select "Play"
Step 4: You can either 1. Fight your friend offline 2. Fight an A.I 3. Arcade 4. Virtual Frontier
Step 5: Select Arcade or Fight an A.I
Step 6: If you select to fight an A.I you can change the difficulty which I rather you go on Very Easy (Unless you're skilled)
Step 7: Select Start
Step 8: Select your Idol, Outfit, and your collab Idol as well.
Step 9: Choose your opponents Idols. (You can't do this in Arcade mode)
Step 10: Choose your stage. (You also can't do this in Arcade mode)
Step 11: Fight
Step 12: Once you win (or lose) you have 3 options: Rematch, Choose Idols, and Leave.
Step 13: Do whatever the hell you want.

I might add more stuff soon, like character specific moves, Strategies, or Tips and tricks, but you can just tell me in the comments what you want me to add. (Or you guys could just make a wiki)