Youtube has some great puppy training videos. Look up crate games for one. It should hit on others for you. Carlos Rojas is in NJ. Look him up. Not sure if he does puppy classes or not, but could probably recommend a trainer. It can sometimes be better for you to take a private lesson once a week until the both of you get the hang of the training. I did privates for at least 6 months I think before I added a group class. If the puppy is getting board, maybe you are spending too much time training or maybe it is too formal. I have no idea, just offering ideas. Do not train on a full stomach either. You should be feeding at least twice a day. Work your pup a bit before both meals or even just one. How many weeks is your pup? That is how many minutes your training sessions should be right now.
My puppy is 9 weeks and I use his kibble to train him. I was told to feed him two cups a day and I break that up into 4 meals. With added treats eqch time. So half cup of kibble with added treats.