Listen to all the advice people are giving, there's been some great advice on these posts.

Try buying a can of PAM (Provent-A-Mite) online and use that to get rid of any mites the snake may have. Just follow the directions on the can for proper use.

You can also go to a Petsmart or Petco and pick up a bottle of Jurassi•Mite. I used that for my male normal BP when he had mites and it definitely got rid of it all. With this product you can actually wipe the stuff on the snake with a rag (allow the snake to slither through the rag to get the product on it) and that can get rid of the mites on the snake.

Taking the snake to the vet isn't a bad idea either, you can get a fecal done and see if it has any internal parasites.

After handling the little snake over a period of time it'll become quite nice and like any other Corn kept as a pet.

I have a WC Common Kingsnake that my cousins' aunt gave me over a month ago. Surprisingly she is really tame and never has once attempted to bite, strike, or even musk on me. She's also eaten every mouse I offered to her which is great news to me, especially since she's a WC snake too.