Hi and thanks for using Petco Pet Education Center, formerly Petcoach!
From what I can tell via your photo, this looks a lot like puppy pyoderma-a very common condition among young dogs. Essentially, these are "pimples" for puppies and usually caused by staph bacteria. I will usually try to rule out any underlying flea problem resulting in pustules, etc when I see these patients. If I see nothing else of concern I will usually prescribe antibiotics for 10-14 days at which point the breakout has usually cleared up.
I would recommend seeing your vet to do these things as well-Lala will be much more comfortable without pustules. I hope this helps!