I would suggest some socialization and obedience classes.
Since you got him at such a young age (puppies shouldn't be taken at 5 weeks) the puppy lacks what they would have learned if they stayed with the mother and litter.
We give dogs time we can spare, space we can spare and love we can spare. And in return, dogs give us their all. It's the best deal man has ever made. -M. Acklam