Sorry I just saw this (been moving my daughter into her new apartment), we are in the middle of puppy training 1 at Petsmart. As far as other dogs in the store, The trainer asks us to immediately bring our dogs into the training area before class. Do not allow them to mingle with other dogs until after class is over. We do not have a full training area of dogs so it is easier to keep each dog separated. If a dog in training will not concentrate he bring out this fence thing and puts a sheet over it so the dogs cannot see each other. It makes for an easier learning session if a dog gets too excited. It works really well, there is a Bichon in the class who will only concentrate for just a little while then only wants to play.
Toby is really great at concentrating in class IF you bring high value treats with you. He is food driven and wants to work all the time to get the yummys! The trainer loves to use him for demo's for everyone. The hardest things to get him to do RIGHT at home is loose leash training and recall each time. We work HARD at home. We worked in the house on the first day and put the loose leash training into practice on walks after that. I am finding that Toby is a day dog right now in loose leash training. He will listen and do what he knows is right(most of the time) during the day but taking him for a walk after dinner he will not listen and turns into a mess. We just keep trying. Our trainer says this is the hardest thing for the dog to pick up so it will be lots of practice for a long time.
Toby recalls sometimes when using the word "come" but if you say his name - then when he looks at you - you say "yes" he will come straight away because he knows that is the Cue to get a treat. I am hoping that soon I can use the come command and he will come straight away but for now I am ok with the way he does this.
Toby is great at tricks! Our trainer says that these things are taught in the advanced class. Toby needs the good manners and behaviors so we work hard on these things.
Your trainer should be available to you after class so you can ask questions. We are on week 4 of 6 and each week I have pulled him aside to ask questions. He has shown me some things for Toby to do for issues that we've had with him that others do not experience. He has pulled out some tools from his bag of tricks for us to make for at home training.
If you have questions please speak up. Our trainer told a german shepherd owner that he will to do private sessions with their dog because the dog will not work during class. All it wants to do is sleep and stare (although the dog is way younger than the rest of the dogs). Not sure if they have to pay more or not but the trainer is willing to take special time with this dog.
Biggest things to remember for the classes:
Bring the dog in hungry
Bring snacks that are a variety and some high value snacks that the dog does not get everyday
Do not allow the dog to mingle with any other dog before class (our trainer allows them to play after class)
Ask questions after class (if the trainer says no then this is not the trainer for you)

If you have specific questions on training sessions and what we are being taught, please PM me and I will try to explain.
It is frustrating when you are working hard at home and he will only do things sometimes but as I keep being reminded, he is a baby and it takes time.