Share 'Now what'

Okay, so I've created an avatar and I'm half-way done with orientation island. Do I need to finish all of the orientation? I got a little bored with it, and I'd rather just leave orientation and learn by trial/error. Also, how do I join a group? I found the librarians in second life group, but then I couldn't figure out how to join. And finally...what should a newby do first, after getting off…