StuartsMom, this is normal and there IS some helpful advice out there!
You've got a "baby" dog on your hands (but please do not misread this to mean this dog is a baby)........and when you are getting him to do something he doesn't want to do......he's throwing a FIT! That's the best way I can put it..........he's being a BRAT. He's trying to do what HE WANTS TO DO! You need to be consistent in teaching this dog what is and is not acceptable. Obviously, growling and showing teeth is not acceptable. BUT, he is still a puppy.
What kind of training schedule do you have for this pup? What are you working on with him to let him know what you want from him? You've got to start there. Sure he might growl but that does NOT mean he is going to grow up vicious.