Don't try to keep up with the fast C group riders. Some of them are sand bagging and should be in B group, but ride C to get more open track, sort out their bike settings, or to have fun buzzing the noobs. Just stay mid pack or back of the pack unless its boringly slow. Also, some track days have instructors that go out with C group, try to get on one of their tails to learn the lines. I see so many noobs that thrash around trying to go fast and miss every breaking point, only to make up for their mistake with more throttle out of the turn. You're not really building up much skill by doing that. In fact, you just piss people off behind you by being so completely erratic, and scaring them to go slower thinking you're about to bin it (which usually happens). If they offer classes in between sessions, make sure you go because the instructor will point out where the breaking markers are. Once you can comfortably find all the markers, then pick up the pace. I think of it like playing pac-man in real life, where you want to collect all the dots, in this case the markers are the dots. Nearly every crash in C group is because the rider did not know the line and overshot the turn. Some tracks have a suspension guru that will sort out your settings as well for a small fee. It's more than worth it to get your bike properly setup and balanced.