I have a Kenyan sand boa, it’s a great species, I’d definitely recommend it as a first snake (it was my first snake). I got my girl as a middle aged adult, and I actually see her above the substrate fairly often, sometimes even during the day. So don’t believe people who say that owning a sand boa is like taking care of an empty enclosure because you never see them. Most snakes are shy and reclusive by nature and tend to hide a lot. A sand boa is no exception, but they do come out and cruise around. I think they probably do stay buried more as babies, but I see my adult out and about a few times a week.
Aside from that, they’re good eaters (by reputation, sand boas tend to have less feeding issues as babies than hogs), they stay a very reasonable size (as adults, they’re big enough to be robust and sturdy while still being small and very manageable in terms of enclosure size), and they tend to be quite docile…and even if they do bite you, they’re not going to do any real damage. They also strike sideways, which is really cool. And their wild type colouration is gorgeous, and they also have some beautiful morphs.
A sand boa is probably going to be less expensive than a hog, even if you want a morph. Definitely something to consider if you’re on a budget. Enclosures for both will be really similar, so price of setup will be about the same for both, but for the snake itself, a sand boa will almost certainly be cheaper.
Keep in mind that hogs are rear-fanged venomous, while sand boas are non-venomous. Hognose venom is not considered dangerous to humans, and it’s unlikely one would envenomate you even if it bit you, but it’s still something to be aware of with hogs. You’d also want to be sure it’s legal to keep hogs where you live. They’re disallowed in some places, either because of their venom, or because of laws protecting native species in their natural range.
None of this is meant to deter you from getting a hoggie if that’s what you really want. Hogs are amazing and the people who keep them adore them. I just feel like sand boas don’t get enough love, and I think they make excellent first snakes.
Some other species you might consider are corn snakes, king snakes, milk snakes, garter snakes, rosy boas, and African house snakes. Those are all pretty hardy and easy to care for, tend to be quite handleable (though some may need some socializing as babies to get them comfortable with people), and have a relatively small adult size. It honestly just comes down to personal preference and what appeals to you.