Grammanan, when all is said and done, the most important part of any class is that you came, you saw, you listened, you talked, you experienced, and that you went home feeling that you came away with more than you arrived with. No class is perfect and I think this thread has allowed some of us to vent a bit, but maybe not in an encouraging way.
Go to your class with as much prepared material as possible, but remember that the instructor may do things differently than your Youtube vidios. Does not mean that any of them are wrong--just different. I LOVE paper pieced blocks because you always get the perfect block in the end. Yeah there are some learning curves to achieve it but heck, IT WILL BE A PERFECT BLOCK (excuse my yelling).
Stop being scared. I will bet that there will be someone in that class that is more afraid than you. Just take a big deep breath and go for it!