League of Legends (LoL) Question: I do not know what to do

It's not an easy champion to pick up early on, but if you really like him it's a good way to start to learn more advanced mechanics.

Also, needless to say, I'm talking about normal mode. It's not a good idea to play a champion you don't know in ranked.

Playing your best champ without knowing how to play the game well, isn't usually going to end up in your favour, especially if the enemy lane, even though isn't "fluent" in their champion but knows a fair amount of what should be done when etc. Knowing how to play the game will, in my opinion, have a greater impact on your entire team rather than trying to carry alone. However, you can get away with this in lower elo, not so much higher up.

The game is about making plays all over the map, its not just a farm fest anymore, which means knowing how to farm, when to ward and when to cut your loses make a big part of how easily you are going to win. The part where you are good at the champion you picked only really makes a difference if the enemy picked a champ that they are slightly less experienced in compared to yours.

You can play ANY champion you would like, and role and at any time of the game.
True there are some champions that easier to learn the mechanics the items, but easy is not the names of this game. To get better you have to do 3 things:
1) Learn from your games and mistakes - you must say to yourself there was a problem to start fix it.
2) Learn from others, watch videos, look for guides and ask players around, you will get a new perspective about your game play.
3)Have fun, You must have fun. Not 100% of the games, but games goal is fun to the gamer. This fun will give you the drive to continue playing and learn even if you lose. remember it's a team game and you can't play for others.

2 tips about the game:
1) give a champion some time before you change, you can't always feel him from the first gameplay
2) Try find a champion you like and play mostly him, after you are good with the mechanics it much easier to learn the macro of the game.