Hard time getting bp to eat

I went to petco to get mice for my corn snake and they gave me a ball python for free was having a hard time getting his temps right but everything is perfect now and still can t get him to eat did they give me a sick snake how can I get him to eat the first feeding day I end up leaving mouse in over night and he never ate it gonna try and feed him again today any suggestions

How long have you had him?
What are your temperatures?
What kind of enclosure do you have him in?
How many hides does he have?
What is your humidity?
Details are important.

Don't ever leave a mouse in the enclosure with your snake for more than 30 minutes, if a does not take the food within that time, he will not accept the food at all.
Leaving a mouse or rat in the enclosure with your snake for extended periods of time can cause the mouse to get hungry and hurt your snake.

There are many threads on the Husbandry forums on here that can help you figure out why your snake is not eating and correct the issue.

BP Husbandry: https://ball-pythons.net/forums/foru...2-BP-Husbandry

BP not eating: https://ball-pythons.net/forums/show...-hatchling-101

Congratulations you have just learned the hard way why petco and petsmart should be banned from selling reptiles.

Follow the information valentiine posted about a BP not eating. You have a stressed snake with an unknown feeding history and now you need to work extra hard to fix that stress and find the proper feeding be it live or frozen thawed. Follow that guide and do what it says to get a young snake to eat.