ASVZ with no experience?

Hey, I (21m) am now entering my 3rd semester at ETH and I would like to do some physical activities for my health, however going to the gym was and is to me one of the most boring things on this planet. However, I've always liked Volleyball in Gymnasium and I was wondering how this works at ASVZ. If I sign in for a courye that is for "alle" but I don't know the exact rules of the game etc. how will I be able to play with the other people there?

Thank you for your advice and have a nice day ^^