You can start house training your puppy straight away. Exercise him frequently in the area you want him to "go". At first it will be coincidence. But if you consistently take him out as soon as he wakes, immediately after meals and just before going to bed, the coincidence will become habit.
House training usually does not happen overnight but lavish praise for correct performance will bring the quickest results. You should find your puppy becoming house-trained within a few weeks.
Incidentally, if he does go in the wrong place, do not scold him (and never rub his nose in it), as this is a very ineffective method of training. Praising the puppy when he has got it right is quite sufficient and effective training.