Sure thing my anonymous compatriot.
League of Legends has been the greatest time sink I have ever gotten into, but I would be lying to you if I said the community was, at best a bit rude and at worst a bit infuriating.
The game most certainly has a steep learning curve to it, and some of the less patient folks in the community will be irritated at new players.
So if you want my personal advice, play with some good friends who will not be bothered by how trash you may be to start. Also the game has a very effective built in mute button, using it to the fullest extent will almost certainly imporve the experience when people get a little bit too chatty about how angry they are at you.
Better they blow out a vein talking to themselves and meeting no response than you join them in the anger having.