How do i get my cat to stop biting?

my cat is about 7 or 8 months old and is still energetic and playful like a kitten. the problem is, he wont stop biting and scratching. we dont have the money right now to get him fixed or give him shots, or to get his nails removed, so that not an option. does anyone have any tips or tricks to get him to stop? thanks!! :)