Just go and have fun.
You should be handling your dog, not the trainer. If the trainer wants to show you things, hopefully s/he'll have a demo dog and not use Yoschi. I think your trainer will be working on you as much as Yoschi, footwork, positioning and line handling is important.
Always end every session on a positive note, and crate him after your session.
I'd get the book from Sheila Booth Welcome to Dogwise.com
it has a great foundation for puppy chapter, and helps to understand different training exercises.