LOL@ at the post from the new guy saying to save your money and just buy a rack. So true...
If you're in MA I would recommend checking out NHreptile.com. They're driving distance from you - I got my first morph there for a good price.
I would buy a female first if I had to do it over again. There's a good chance you're going to get hooked and try your hand at breeding and you'll be happy you had a female when you do. Honestly when you buy them you think it's going to be a big animal but then by the time it becomes an adult it's actually quite small.
Definitely feed in the enclosure - ball pythons don't get wild about feeding. It's very unlikely you'll get bit once you learn to tell when the snake isn't interested in hanging out or when it thinks it's dinner time.
As for the tank, you should be pretty much fine if you give a big water bowl and cover most of the screen top like the tutorial shows. It's pretty humid in MA most of the year so don't worry too much about the substrate. You might want to mist lightly once or twice a day in the winter when you see the snake getting ready to shed.
GL and welcome!