Your first masters swim meet

I did it. I finally got the guts to sign up for my first masters swim meet. I am a little nervous (ok a lot nervous!) about it. From what I have read on here, the atmosphere at most places is pretty friendly and welcoming. Would anyone like to share anything with me on what to expect? How different is it than an age group (other than the obvious lack of kids and parents running around) meet or a high school meet? Those are my only meet experiences. I don't think that it is a large meet, but I am a little nervous about how this whole "masters" thing works. Thanks!