A young puppy is very easily distracted. If he does something at home, clean it up if he doesn't see it and make the place odorless. This is to prevent him from thinking that that conscious place is his "WC". Don't punish him, grumble at him, and ignore the incident.
Fearful puppies can be tricky to work with. If not managed well, your puppy could grow into an under-socialised adult dog. If you recently adopted a dog who has fear or anxiety issues, he might react badly to the presence of a stranger, be “untouchable”, or not able to accept