If you want to learn to shoot a handgun, a 22lr is best for most people. A good semi-automatic 22 is generally cheaper and easier to find than a high-quality 22 revolver. Lots of double-action 22 revolvers have horrible triggers. (I learned on a single-action Ruger Single Six as a teenager.)
My first "real" handgun was a medium-framed 4" 357 revolver. If I could only own one handgun, that is what I would pick. It can shoot mild 38's or crazy 357's. It is effective for almost all North American game animals, if you are skillful with it and get close enough. It's a good HD weapon, and you can CC it if you have to.
I've taught quite a few people to shoot, and they seem to generally find that a revolver is easier to understand right away (intuitive). With a semiautomatic they have more opportunity to get the controls confused, get some part of their hand whacked by the slide, limp-wrist it, etc.