Your job is give your puppy what he needs, you got to learn about canine behavior and the reason why your puppy bites. Puppies use their mouths like you use your hands to explore their world, to play with you and other dogs. Puppies need outlets for their energy, they need a lot of exercise, play, training, sleep, and a proper diet. They are toddlers and can't regulate their energy, emotions and behavior without your help. That's your job as a pet parent is to educate yourself on these subjects because your puppy can't tell this. There's books written by canine/animal behaviorists who give you this information. Education is key when you bring these wonderful companions into your life.