Having ridden with N2/NESBA for the past 10 years, I would highly recommend them, especially if this is your first time on the track. Yes, there is a Novice group meeting that one attends every track day with them, but they will stress to you that safety is their #1 goal, with the rider having fun a close second. I met several new to N2 and/or track riders at NJMP this past Monday, and everyone complains about the passing rules. The truth is, and it's repeated often, is if you are that skilled/fast, you can pass people easily in any group, within the rules (someone mentioned leaving ego at home). There are plenty of passing places at NJMP even in the Novice group. If you're looking for a bump to the next group, either line up first or ask a coach if you can be evaluated. From my experience, those that get bumped are noticeably faster/smoother than the rest of the group (try watching from the bleachers sometime), but speed is not a prerequisite for getting bumped.
I also believe the demo program is different than the new rider program. New riders can ride their own bikes for free for the first two sessions, then sign up, if there is room in your group. The demo program involves taking one of the Yamahas out during your session. Regarding what to bring to the track, besides chair, shade, etc., don't forget sunscreen and ear plugs. There are rooms you can rent above the garage at NJMP which are about $100/night, and the convenience is worth it to me. Give them a try; you won't know if you hate it until you do.