The schedule
Take a young puppy out: right after waking, after eating, after drinking, after play, and every 45–60 minutes otherwise. Overnight, expect 1–2 trips for puppies under 4 months.
Pick one potty spot. Walk straight there on leash, stand still, and wait. No play, no chatting.
The instant they finish, mark ('yes') and feed 2–3 small treats. Then play or walk as a bonus reward.
Supervision indoors
If you can't watch them, they're in the pen, crate, or tethered to you. Free roam is earned after weeks of dry days.
Learn their 'I need to go' tells: sniffing in circles, pacing, leaving the room, suddenly stopping play. Scoop them up and head out.
Accidents
If you catch them mid-stream, interrupt gently with a cheerful sound and rush outside. Reward whatever finishes there.
If you find it after the fact, that one's on you — clean it with an enzymatic cleaner. Don't scold or rub their nose in it. It teaches fear, not bladder control.