Kittens/cats are true carnivores and as such have unique nails that are sharper and more curved than any other mammal. In the wild, this would help them grip their prey. Kittens/cats have a natural instinct to scratch too because this helps them to mark their territory (both visually and using scent glands in their pads), to stretch, and to sharpen their nails.
Here are some tips to help prevent being scratched/bitten by your kitten/cat:
Start trimming your pet’s nails as soon as possible. Your vet can show you how.
Make scratching posts readily available.
Never use your hands to play with your kitten/cat
In the event that you do get scratched/bitten by your cat or kitten you should wash the area immediately with warm soapy water and if necessary consult with your doctor.