[sweetlee]

Oh wow. I bet you are overwhelmed.
I would not take my guy to a class with 18 other dogs either.
After some private training, and getting a pretty good handle on the basics I would still recommend a group class. It's good for them to be around other dogs for distractions, and to make them focus on you. I would just find a much smaller group.
As far as the nip you received, I bet the dog was just really worked up and actually nipping is play behavior for dogs, watch them play with each other and they nip and mouth all the time.
She just probably hasn't been taught not to lay teeth on people.
Stick around, you will learn lots.
I am glad you took this girl in, and you won't regret it once she is trained. The difference between a trained dog and an untrained dog is unbelievable.
Keep us posted.

Sharon