You get 3 champion picks that you can use throughout the game.
I can teach you for a 1v1
Builds for 1v1 mostly depends on your starter items, as most games end before you can really get anything.
Also, try to pick mages or good early game champions, picking carries is a bad idea. So I would't really recommend teemo unless your pretty confident you can get first blood. Oh, and the first few rounds it's a single elimination, so once you and i get out, we're our for good, but at the final 8 we have two chances to try to win. The final 8 will also be livestream. My goal is to make it to the final 8. xD Don't let me down!! Though, that's a high goal. We will need luck at our side. I just hope we don't get matched up against megazero or some other pro the first round G__G. When I see you in game I'll give you some practice. Look at the last tournament picks and see if you like any of them, if you do than you should choose those as one of your 3 picks.