What a clan is: https://www.warzone.com/wiki/Clan
. The list of clans can be found at https://www.warzone.com/Clans/List
. The benefits of joining a clan and how to get invited to the clan are usually be found in the description of a clan's clan page. Responsibilities of being in a clan include being active - joining games/tournaments, teaching/giving advice and managing clan members (if you get given manager rights).