When bringing home a new baby I usually let them get acclimated for a week in their new enclosure, then I will start handling them for 5-10 minutes twice a day so that they can start getting used to being handled, then start increasing the time you handle weekly. I offer food after the first week, if not taken then I will try to feed on the same day the following week. General rule of thumb is not to handle the snake for at least 48 hrs after feeding (there is a possibility you could get your mouse back). Is this snake coming from a pet store of breeder?

Hope this helps

Take care