When you start out dog toilet training you need to give him a place of his own, maybe a corner of your back room. That should be where you put his food and his bed and his toys and cover the whole floor in newspaper. When you leave the house make sure he is in that room and can't get out.
When you are gone he will obviously need the toilet and will go where he is standing, but over time he will pick a place and start to do his business in the one place, when he starts to do that you can then start to remove the paper from the area furthest away from his chosen spot.
Gradually continue this until it is only a small space available for him to go, if he misses the paper then you are moving a little bit too fast and need to go back a step or two until you get to as little papers as possible. When he gets older he will be able to control his bladder movements a lot easier.