Welcome!

A 55g is pretty big for a ball python! Lots of people keep them in 10g tanks when they are young and then move to 20g long tanks when they are ready for that. Never keep two snakes together in the same tank unless you are cycling them through for breeding.

As for equipment, you'll need an under tank source of heat as well as a thermostat to control that heat. You'll also need a thermometer and hygrometer for measuring in-tank temps and humidity. Also, you'll need two small hides and whatever you choose to use for substrate (newspaper, aspen, etc.)

Also, food! Yes, your new snake will need to eat and so make certain that you have a reliable food source locally, or a place on the net to order rodents from.

Again, welcome! Ball pythons are great starter snakes as they don't get very big and are relatively easy to keep. Just make certain you have a thermostat (about $100.00) to control your heat source