I got my boy at about 10-weeks. I immediately put a litter box down with a peepee pad in it. I would constantly put him in it and tell him to go potty.... after everytime he ate, everytime he played, everytime he woke from a nap. He did really really well..... I told my vet I was surprised how quickly he picked it up and she told me to keep in mind that their Bladders are Not Fully Formed until they are about 16-weeks. I would just Maaajorly Praise him and give him a teeny treat anytime he was go onto the peepee pad.
Good Luck!!