Well there are a few things you could do. You could find an [OPEN] thread and post in that, generally your character should have a good reason for being wherever the thread takes place though.
Alternatively you could start your own open thread and hope it doesnt get too chaotic.
Start with the forum rules. From there write your character profile. Next, do what Joy suggested. You're welcome to participate in [OPEN] threads- though I would caution you to inquire with the OP. You know? Courtesy and all.