Welcome Pete! Hopefully you'll find the NESBA contingent to be friendly and helpful. There'a alot of great people associated with this organization, and you're sure to find whatever help and tips you need along the way. Don't be afraid to ask questions. Be sure to read (and re-read) the rider's manual, as many newbie questions can be answered there.
Depending on the track you ride, the group size will vary. Bigger tracks can allow for larger groups, but the dates are never overbooked. Some tracks fill up quicker than others so if you've got a date in mind, sign up quick. Living in VA you've got a solid choice of tracks, so you shouldn't be without plenty of options. (VIR, CMP, NJMP, Summitt Point....)
Can't wait to get out there... first date for me is Jersey-Thunderbolt in April. If you make it to that one, stop by and say HI.