So I've never had a puppy before, I've had full grown dogs but never a puppy. A few months ago I got Sebastian, he is about four months old now and he's learned some commands sit, shake, lay down, roll over, come here. Right now were working on some of his rough spots; he's a little nippy/mouthy, he gets excited and jumps up, and he likes chasing the cats. I know that these are pretty common things but I just don't really know how to go about correcting them since he doesn't really respond to most of the things I've tried.