If you have completed your first day at the school doing Level 1 and you are pleased with your results, then the 2 Day Camp would be Levels 2 and 3. There is nothing stopping you from doing levels that you have completed more than once. From my experience, after completing Level 1, I took Level 2 the next day because of how much I learned in Level 1 and what mysteries must be waiting for me in the next levels. I was not dissappointed.
The advantage to taking the 2 Day Camp is that the instructor to student ratio is much better, the track sessions are longer and there are more of them. Not to mention being able to drill on the specialty bikes regardless of your level.
As far as the instructors keeping track of who is at what level, we are assigned specific students and given details on each student that we have. We each keep the same students all day. The bikes are numbered wether you ride a school bike or bring your own and most times, students who are taking the same levels are generally put together.
Level 4 is the highest you can go. Don't be dissappointed to hear this though. Programs are customized to fit you and are modified throughout the day as your skills improve or if you just want to work on one thing only. Your instructor, the Level 4 liason and Keith make those decissions as they discuss your progress with you. This level is meant to be "about you, the rider" and having several sets of eyes watching you improve. I know as an instructor, I have 5 to 7 other instructors watching me every time I am on the track and pointing out things here and there that would make me become a better rider, and it has paid off many times over.
Good luck and I hope to see you at the school.