A clan is a group of ppl that play a game together.
The point of a clan or league is to have fun mostly. Also in a clan you have a better chance of having someone for a 2vs2 in a game and also you know how to play so you play better. Some league when you are big they have internal battle,ladder and other thing. Some have rank also which you recieve when you are active or getting good at a game.
Join LastStarfighter league. One of the oldest SW league and most respect league to ever exist