ball pythons are great snakes, they're very calm for handling especially as babies as they tend to just ball up and let you hold them, as they get older they become more and more active during handling and they are very slow moving, deliberate snakes. they are also pretty hard to get them to bite, their first line of defense is to ball up and hide from any threats, hence their name, in my experience they also make it very clear when they're not in the mood to be handled, if I go to pick mine up and they give me a hiss, then I understand it's not a good time for them and I just try again later on. also if you were to get a male, it will grow to be around 2.5-3 feet long so like I said not huge.

another option is a hognose, while they technically are venomous, they're rear fanged, meaning they REALLY have to chew on you to get you with their fang, on top of that, their envenomation can be compared to a bee sting, some people react and get pretty severe swelling, others just get a bit of pain and a swollen finger for a day or two. that being said they do NOT bite defensively, the only way you'll get bit is in a feeding response. as far as defensive behaviours go, first they will flatten their necks and hiss very loudly, trying to imitate a cobra, if that doesn't work, they will writhe around, flip on their backs, stick their tongue out and play dead. after that they will strike defensively, but they'll keep their mouth closed, so they pretty much just headbutt you, it's beyond adorable. they're generally easy to get on feed and they only grow to be 2 ish feet, and thats even a big female size.

you could go with cornsnakes, but when they're babies they are quite darty and squirmy so you would need to be a bit more careful when handling a baby that it doesn't squirm out of your hands, and they do calm down when they get older, making them much easier to handle.

also kingsnakes, milk snakes, neither of which I know much about aside from the fact that they don't grow to be exceptionally large and can come in some pretty cool colours.

hopefully my short novel can help you out a little bit, and of course if I've provided any incorrect information, any other experienced keepers please correct me.