The tail will heal and grow back with time. The kitten may not even notice that it’s gone, but it can be replaced once the cat is weaned and able to hunt for its own food (and neutered/spayed).
How do I tell if my cat has a broken leg?
If your kitten seems uncomfortable while trying to walk on three legs you should take him or her to an animal hospital immediately.
Should I try soft foods first before feeding my baby chick formula? What should I feed the first couple days after birth? Do kittens eat small crickets/grasshoppers?