If you're panning not to use any, tell him. Make sure he understands that you won't be squirting the dog for barking, or collar popping for misbehaving, or forcing the dog to do an exercise he hasn't learned yet. It's a common request. Second, to lessen the stress on you and your puppy, try to work a week ahead of everyone else. Call the instructor and ask what behaviors will be practiced in the first class.
Attention is the single most important thing.
Put him on a six foot leash. Don't call him. Don't wave food around. As soon as he glances at you, click and treat. Lots of boring heeling drills.