First off, welcome to BP.net. You will learn a lot on here.

I would not recommend putting a baby ball python in a cage that big. I wouldn't put a hatchling BP in anything bigger than a 32qt tub or a 10 gallon tank. If you want something that can go into a cage that big I would buy an adult male or female.

If you are set on getting a hatchling, I would highly recommend having a small setup ready BEFORE you bring the snake home. Temperatures need to be around 90 degree for a hot spot have an ambient temperature of 80 degrees. Use the search function on here to look at other members hatchling setups.

If you can't get the basics of a properly sized cage finished before the show you might be able to find a local breeder in your area. You could pay them the money up front and see if they will hold it for you until you have the proper husbandry. Then just pick it up when your ready.

Please do not bring a BP home without having everything setup properly. It will stress the snake out.

Have fun at the show. You must be very excited! Post some pictures of it if you can.