Our guild has 2 meetings a month. The first one is a business meeting first and then show and tell, and if there is time, a short presentation by a guild member. The second meeting is a doing meeting. This is where we work on a specific project that is usually taught that night. There are supplies to bring for that meeting.
If you have a LQS, usually someone there knows about what is happening in the guild, you might want to check with them. If that's not an option, just go and relax. I am the current president of our guild and try to get visitors to tell a little about themselves.
I do think that most guilds look forward to new members. I think they bring a new perspective and interesting ideas to the mix.