It's the best thing you can do for both your puppy and all the people he will interact with for the rest of his life. So many dogs came into the veterinary clinic where I worked who were great dogs... until you had to draw some blood or cut their toenails. Then it would take a couple of people. Maybe a muzzle. Lots of sweating and swearing and eye rolling on the staff's part, and an embarrassed owner.
You don't want that to be you. So handle your puppy. Hold him in your lap, rub and look in his ears, handle his feet, pull gently on his legs. Lift up his lips and check his teeth. Hold him in your arms like a baby. Stand him on a table or the floor, and wrap one arm around his neck and the other underneath him and around his middle (like someone's holding him for the vet to give an examination). If he squirms or mouths or has a tantrum, persist, gently, quietly, and patiently. Keep in mind that he's a baby. He's learning. No discipline is involved here. It's unfair to discipline a dog for behavior he hasn't yet learned. Later, for bratty behavior, that's the time for the sterner voice, a little spark when you make eye contact. Now, it's gentle, firm persistence, until you get an approximation of what you want. You'll come back to it later, and eventually it will be perfected.
He will learn so many things from this. That people can be trusted. That he needs to stand quietly for the vet or groomer. That it's people who rule his world, no matter that he thinks he was born crowned king. Push on his butt. Grab his collar. Pet from head to the end of his tail with long strokes. Grab the end of his tail and pull lightly. Gently pinch and lift the skin on his back and sides (these are tender areas, so you MUST be gentle here). Teach him to walk being led by the scruff of his neck (This doesn't hurt, but it feels weird and bossy so proceed appropriately, it's a very good lesson for him to learn.) Remember that this should be a positive event for your puppy. If you hurt him, you're ruining any progress you've made. So keep it light.
Teaching a dog that humans can touch him anywhere, anytime, is a necessity. It will reduce the likelihood of a bite when a neighbor's kid grabs him around the neck. It will make it easier to draw blood for his heartworm test when he's at the vet. Obedience training will be come more naturally to him, because he's already learned to look to you as the leader. It makes your dog a much better citizen overall. Because a dog accustomed to being handled is much less likely to bite. Once again, it comes down to giving your dog the tools to be safe in his environment. And for the urban dog, that environment contains a multitude of well intentioned but not necessarily dog savvy people. So keep everybody safe. Go hug your puppy.