If you are lucky enough to get a 7-week-old puppy, there is no excuse for any bad habits to develop over his lifetime. Puppies learn INSTANTLY when they are that young, and if you use the proper training methods, gentle but consistent, he will behave like an angel his whole life through.
The most important training, of course, is housebreaking. Boys are easier than girls because exploring outside is their favorite thing. They just cannot get enough of all the new smells out there!
The main key to housebreaking is watching. Watch your puppy AND the clock. Once every hour is not too often on a day he is active and the weather is good. The younger the pup, the more often he needs to go out, mostly because he is growing so fast. He must drink more water to fuel his metabolism than he does as an adult. Also, since he eats three or four times a day, you know what that means.
Watch him for subtle changes. If he is happily chewing his toy, and gets up suddenly with his nose to the floor, move quickly! He is ready to squat! If he has had a nice nap, get him out of his crate and outside right away. If he has just had a good grooming, it stimulates his circulation...