[Maxxx]

First off, please don't hold your puppy down. It scares them and intensifies the situation. Always redirect and praise. If he's biting something he shouldn't, stick one of his toys in his mouth and praise like crazy. We had toys all over the place when Max was younger so one would always be available.

In reagrds to him pulling, if he pulls, turn around and go the other way. When he follows praise. Keep doing this until he understands that pulling gets him nowhere. Also, treats for him staying at your side work wonders.

To calm him down, if you don't have a crate, get one and give him a time out in there with his favorite toy and treat. At that age, 2-5 mins will do. Just remember to make the crate a great place for him and he won't mind being in there for a time out or nap.

In regards to your nephew, I'm sure you pup was biting him because they were running and playing and you pup thinks your nephew is a littermate. I'd stop them from playing asap and teach your pup to not bite at clothes because that's the same thing as biting skin. Lots of redirection with toys and praise will work here too. Anytime he gets skin or clothes, stick a toy in his mouth and praise him for chewing the toy.

Good luck!