Since you mentioned it, for team-related stuff just hang out in Battle Center. :) You can rate other people's teams, etc, and actually battle in quick battle thread/tournaments/etc. PLUS there's a Community Day today well, in around 3 hours, so if you come to the server, linked in the section you can meet with the rest of the battling community here ~~~
As for friends list, go to your usercp, check on the left, and it'll have friends/contacts, then just click there and add someone that way, or via their profile on their friends list "add this person to your friends list", iirc on the far left.
Welcome to PC anyway n___n