I have been playing this for a while now but since I've unlocked teams it literally will not let me join a team, either saying there's not room left (when there clearly is) or there not accepting anybody. But every single one! I haven't hacked or anything btw. Please help!

You are trying to join teams that are open and had someone join right before you. When you see it say 29/30, that could be a delay of update when in reality it's already full. Other teams may be full or require application. This is common when doing the simple search to find a random team and join.

Lower your sights, try to join a team that is not as desired or has more than just 1 spot and you may get in.

Byjd1Please