I would suggest teaching OTHER stuff… yodel, talk, roll over, High 5, shake hands....
while YOU may think growling would be cute...
it will be the ONE person that doesn't and feels the dog is bring agressive towards it.
OR even worse... another dog thinking yours is getting aggressive and NAILS him for starting that behavior.
I also agree with Pat and Lisa, that a pupy should not be in its new home at 6weeks of age. It should be learning social skills from it's mother and siblings. I am hoping you also got your pups fanconi results prior to purchasing him. Of course, I can't imagine the results would be back already since it becomes fairly easy to get the fanconi swabs once the pups are 3 weeks old.
Where did you get your puppy?
Best of luck with your little guy.