Should I join this (10 points)?

Well the thing is, I came across an open forum to role play a series I like. The problem is that it's got like 50 topics, and 190 thousand posts, and 5,000 people. It's huge and intimidating. I don't want to join something that huge, but I've already spoken with the forum leader, and she kind of pushed me into it. Half of me wants to just because it's the first forum I've seen that's active, for the show in particular, and the other half says it's too freaking huge. I'm jut really confused. What do you think I should do? Please and thank you."