Taking him to the vet is a good place to start. It's been 25 years since I've had a puppy but 6 weeks sounds very young for him to be away from his mother. And young to be infested with fleas/ticks. I'm not surprised that he is making pee/poop all over the house though...take him outside when he does it and be consistent with the term you use for pee/poop, may as well begin housetraining him now. Little puppies can't hold their urine long at all so take him our often.
Where did you get him?
Welcome to BW.
~Denise
Where did you get him?
Welcome to BW.
~Denise