All food offered should be puppy formula of course, start with a wet food or dry food soaked in a little warm water, then slowly convert over to the dry. Puppy food has added nutrients and things a growing puppy needs, the only exception to this is very large breed puppies, puppy food can actually cause them to grow too quickly which can affect their joints later.
After being weaned from their mom, they no longer need milk. Whole milk can cause diarrhea which can result in dehydration. I know this happens in cats, so check to make sure. I sometimes give my cats Lactaid as a treat, no diarrhea with that.