How can I start ?

I really want to start playing LOL, but I don't know nothing about it, can you help me ?

Atleast finish the tutorial in the game to understand the very basic mechanics. Move on to playing a co-op game with bots and learn the different champions. Then later on when you're a bit confident with one champion play 5v5 against humans. It helps alot learning the champions, so try to research them, see how they're played and look for guides on youtube or google.