2 weeks is a blink of the eye (if snakes could blink that is) in a snake's life. Give the snake time to settle in. Also remember hissing doesn't always indicate a willingness to bite. I have a number of snakes in my collection that will hiss every single time you touch them but it's more of a grumbling complaint than anything serious.

Just be patient with a new snake. It's a lot to adjust to for an animal that likely hasn't a clue what's happening now in it's life. Develop simple handling routines that you do over and over. I believe routine helps these animals to adjust better to us. Remember as well that handling is something you want but not necessary to the snake's well being.