Starting from a baby snake, balls are easier to feed for an inexperienced snake keeper. Yes, they can be boring but most people dont give them the time they need. With frequent handling ball pythons can be quite active as they get older and used to their environment. A fish tank is not ideal since it is harder to control humidity and temperature. Its not impossible, you just have to pay attention and work a little more. I keep my babies in 10s and my adults in 55s. While I try to feed mine every week, Ive noticed young snakes tend to refuse food once in a while, even the hearty eaters. After they get a little bigger( over 400 grams) they tend to be very fat snakes who rarely refuse a meal. That depends alot on personality, that is just my experience and the general trends ive noticed.
Corns and milks are great starters too. Kings can be a bit more aggressive but still a good easy choice for a beginner