Okay, lets get your snake up to eating and comfortable
Make sure the enclosure is adequate, you can maintain the right humidity and temps. But more over, it needs tight secure hides.
Don't just leave your snake alone for a week after getting it, leave it alone for a week then try to feed it, wait until it eats twice for you before handling it (you want that to be 2 weeks straight).
Scent the room before offering food. For about 10-20 minutes you want it to be able to smell the food.
Get the food at the right temp, usually this means about 80-90 degrees for the whole body and with the head slightly warmer.
Do a corpse dance for your snake. You don't need to swing the food around, but gently vibrating it and slowly moving it a foot away from the snake until it gets closer to the food to investigate is a good idea.
If you have a live food item, make sure the snake is already paying attention to it before putting it in the enclosure