new to the game need help tips

I'm not very good with the game, but I can give a little advice. When I started, I really went for only one Champion but then realized that playing whoever is on the free rotation is a really good way to understand the game. When you get the mechanics of the game down I think that's the perfect time to see who your favorite is and main them. Watch what the enemy team builds and try to counter the ones in your lane. Understand that champions can counter each other so you might have an advantage/disadvantage when playing. Look at places like Mobafire for guides on how to play your champion.

Overall just keep playing the game and stick with it, you'll run into unending smurfs, but just try your best and learn from every match you play. The more you practice, the better you'll become.