Training should begin the moment you bring the pup into your home. Not serious training of course, but basic training in what you consider to be acceptable good manners.
With gentle but firm handling your pup will soon learn what is expected of him.
It is important to remember, when you reprimand your pup, the correction must be associated with the unacceptable act. In housebreaking him, for example, it is essential to correct him immediately you find him misbehaving.
It is pointless taking him to a spot you find later, pointing to it and reprimanding him in a loud disapproving voice, Or even worse, rubbing his nose in it. Of course he is going to look “guilty”. You may gain the impression that he understands what he has done but this is certainly not so.
If you intend your dog to be a housedog, when you bring the pup into your home for the first time it is essential for him to have a place that he can consider “his home”. Find a suitable place in the house. Provide suitable bedding of some sort – an old blanket, or towel – and let him know that this is where you expect him to lie.