If that cage is made completely of screen like I think it is, it will not hold humidity and heat well. I would suggest a glass reptile terrarium, a 20 gal will suffice for a baby BP. the temps at night can drop lower, in the mid 70s. Be sure to provide a secure hide box on both the warm and the cool side so your snake can regulate its body tempature.
Good luck with your new snake, and welcome to the site. I'm sure you will get a lot of useful information here.