He
is only 8weeks old. He will learn his name in time but for now his name probably sounds like any other word you say....and they probably all sound like BLAH BLAH BLAH to an 8 week old
Potty training takes persistence and TIME !! He can learn if you just stick to a schedule and don't give up. There are many threads on potty training on here. Some take longer than others so it will require patience on your part.
The biting is natural for a puppy , tell him no firmly or squeal a bit and pull your hand away and ignore him for a bit and he will get the clue. Buy him lots of chews and treats because he does need to chew and he will chew on whatever he can be it you or your furniture if nothing else is available.
As for teaching sit and other commands , do you use a treat to help him learn it ? Mine did much better when I found treat they loved.
It's only been five days...let him get use to you and his new environment and give him some time to settle in
