First of all welcome to the site glad you found us!!!!
Second what kind of set up do you have. Heat, hides, size of enclosure and so on. Problems with housing can be the cause of the majority of problems with Balls.
Check this out real good caresheet.
http://www.ball-pythons.net/modules....warticle&id=59
Tap water is fine all mine get tap water.
As for feeding give it a week to settle in before you try to feed, and feed what it was eating before.