League of Legends (LoL) Question: i don't know what to main :'(

What MissMaw said is true, most people just get their mains by pure chance. One day you notice you like playing one champion much more than the rest so you do it. There's also people that don't have a clear main and just play lots of different champions with some minor preferences.

But that doesn't mean you can't go out and try to find a main. My suggestion is that you cut down by playstyle. How do you like to play the most? Staying back and dealing damage? Going in and locking down people? Going in and dealing damage? Assassinating their priority targets? Look for those things and cut down on champions that succeed in whatever playstyle you enjoy the most. You might not like them at first, but give every champion you try some time, at least until you polish some of their basic combos or play patterns.

Both MissMaw and Ekki are correct. One thing I would add is that it helps to know what you like to do in each phase of the game. In the Early game, would you rather play it safe and slowly snowball from killing minions in lane or monsters in the forest, or would you like to be more aggressive early on and try to get a lead by killing your opponents early?

In the mid game, do you want to focus on simply preventing the enemies from taking your towers; or do you want to focus on team fights in order to get ahead of your opponents?

In the late game, do you want to have already won the early game enough that your team can pull you through the late game despite you falling off a bit, or do you want to be stronger than you were in the early game and mid game and hope you can turn around your disadvantages for a win?

It really comes down to when you want to be at your prime. Early, mid, or late game?

People get mains subconsciously, I don't think anyone goes out and tries to find themselves one.

Just keep testing champions out and eventually you'll find one you really like. Some champions require a few games before you begin to like them, so give yourself a few games before deciding if you like some champion. I didn't like Brand when I first started playing him, but after a few games he became my main.

How about not worrying about what to main, just try playing all the characters and have fun! After al, you can play any role and be good with all of em. Eventually after playing all those roles and different champion, you'll get to find one! I started out with jungle master yi, and moved to mid, but now i prefer to play support.

you pretty much have to go meta
also depends on what tier your in.

I remember playing twitch because someone destroyed me in lane when I was lv 17 so I said "I wonder who is this" Luckly he was free I tried him out and loved just how witty and fun he was. That's how I found my main

How i picked my main :

Start a game.
My friend tells me : take Zac, you gonna like it.
Now it's been 3/4 month I play almost always Zac.

So you really should main him.

I think you should just play someone who looks fun :D
I mean it's not about the wins (unless you wanna play ranked.)
I think you should just buy mystery champion shards and see if you who you get looks cool/fun.