
Hi, and welcome to the forum!
First thing - ditch the puppy pads (they only teach puppies that it's okay to relieve themselves indoors, which of course it isn't!) and take him out to the garden to relieve himself immediately he wakes in the morning or after a nap; after every meal; after every play session; and at least once every hour.
As regards the 'biting' - this is normal puppy behaviour, just as it's normal baby behaviour to put everything into their mouths. When he starts it's best to say "No, gently" in a calm-but-firm voice, then either give him a toy to bite on instead or just remove all attention from him for a couple of minutes.
Make sure that he gets plenty of time out for rest and naps - puppies are notoriously bad at judging when they're getting overtired and, just like overtired children, get bad-tempered and emotional. So when you can see this starting it's up to you to calm the atmosphere.
Good luck!