Dog walking question

My family is preparing to bring a puppy home. I haven’t had a dog since I was a kid, and my mom mostly walked the dog.

So… this feels so dumb to ask, but where is it ok for a dog to pee/poop? I know to carry poop bags and clean up after the dog… But is it okay if it happens at the edge of someone’s yard? What about pee? Am I supposed to only let the dog go on the sidewalk?

I have a fully fenced in backyard, and we’ve made a smaller enclosed area for puppy. So I’m not worried about the dog not getting grass time. But should my goal be to train the dog to only go on sidewalks when we’re out?