Hi! Welcome Home to America
& Welcome to YT.
The best way to keep that puppy look is to keep them in a puppy cut. If you don't do your own grooming, hopefully someone here will post of a good groomer in your area. Would strongly advise you stay away from Petco or Petsmart for the grooming. There is the rare good groomer there, but far more horror stories then good ones from those 2 places. Too bad you aren't in the Dallas, TX area, I could recommend a great groomer.
Would love to see pictures and hear more about your cutie-pie.