Dot, Debbie and others are right about it being a good idea to check the place out first, w/o Duncan. I made the mistake of signing Ricky up at 4 months of age at a school that wasn't at all what I liked. They sounded great on the phone though!
I was told they don't use punishment, but at our first class they were talking choke collars, water bottles and sticking fingers down pups' throats to make them stop nipping!
I wanted to run out there screaming! We stuck with it for 3 classes out of 6, but ended up quitting. We were stressed and Ricky was not enjoying it at all. When they made us flip our dogs on their backs so as to be submissive and make them stay there forever it seemed, I said 'enough'. I got Ricky up and waited 'til the rest of the class was done with this 'method'. It just wasn't for me. I have no problem with showing the pups who is boss, but there are better ways in my opinion.
We started at a new place last Sat. and so far so good! You really have to check them out, ask questions about how they teach, correct, etc.. Duncan is such a young pup that what you really should be looking for is a social activity, not an obedience class. Sure, it would be nice to learn some commands and all that, and they should teach you how to do that, but it should be relaxed, fun, not traumatic for the pup and something he'll look forward to instead of dread each week.