On the biting issue, if this is a kitten, he is probably just in the teething age. You can get him a rawhide chip to chew on, or a soft toy and use that instead of your hands taking your hands out of the equation. A peacock feather is a wonderful kitty distraction, allowing you to interact with your kitten without getting bit.
About him hiding, this is a typical reaction to a cat/kitten that is overwhelmed and needing security. Depending on where he came from and what he experienced, just let him hide for now without going after him or making an issue of it, unless you believe he is ill, then get him to a vet.