At 13 weeks old, he has his super sharp puppy teeth, so I can imagine he has drawn blood.
The biting problem is not going to be solved overnight or even in a week. Being a puppy, he is testing his boundaries. Keep consistently doing the yelping, firmly saying "no bite," and withdrawing attention and removing the biting targets like your hands and feet. Stay in control and calm, but firm. If you get worked up, your puppy will be more reactive.
When he grabs something he shouldn't, like the paper, say "drop it." Training for "drop it" or "leave it" is essential. You may have to hold him and work to remove whatever it is you want him to drop. When he finally lets go, reward him. The trick is to try not to let training turn into a fun game of chase when they have something naughty.
Work on training in general. The earlier you start with basic commands like sit, down, stay, the better. Plus it gives them a sense of accomplishment and structure. Having a daily routine of activities, from mealtimes, to brief play and training sessions, and so on will have a positive effect on overall behavior.
__________________ Kristin, Max and Teddy  |