Somebody has to be the slowest and if that is you that is OK. Nobody needs to crash so don't let that be you. Ride your pace, pay attention in class and maintain a steady line. Slow and smooth improves faster than the guy that brakes just after he sees god every turn.
All good advice above. The only thing I would add, based on your question above, is to try NOT to treat it as a "group ride." It's not - you are riding your bike at your pace on the racetrack. There are other bikes around, but the best approach is to be aware of them - that's all. Don't follow, don't focus on other riders. Pay attention to the instruction given, ask questions (the only stupid question is the one you didn't ask), and ride the line - which we will help you find. :thumb: See you there!
My second mortgage account is nicknamed online "Trackday Line of Credit" LOL! Just kidding. Have fun!