I agree. Should be no need for an instructor to drive your car. But I would encourage you to be a passenger in their car...at least a few times. I have learned a lot watching how the more experienced drivers do it. Plus you will realize just how fast you (or someone more experienced) can take specific corners.
My advice: enjoy yourself and ignore other cars...by this I mean, don't let other cars distract you. There will be better drivers, so let them pass...don't just frustrate them in the straights. At my last track event, there was a BMW driver who was very good (had over 10 track events, I had been to 3) and he was very grateful for me letting him pass in the straights...in contrast, there was a guy in a C6 Z06 who refused to let anyone by him and consequently developed quite a few enemies. If someone is catching you in the corners, let them by on the straights. It's about having fun anyway. Oh yeah, by the 2nd day of the event, no one was passing me or even approaching my GT, in the corners or straights!!!