Revolvers are pretty dope, but don't have the capacity and safety features of semi-auto handguns. If you don't plan on carrying, get a mid- or full-size handgun. The extra size and weight really helps with the recoil. 9mm and .45acp are both good rounds for HD, and in the past 9mm was pretty cheap. Much harder to find now. Jacketed Hollow Points are what you want for HD, because the bullets are designed to flatten-out and shed their energy into an object (like a body or a wall) rather than punching a hole through it.

AR-15s are ugly looking IMHO, but really are the best all-around rifles that can be found at a good price. Soft shooters, too w/ not much recoil (tho very loud). If you don't want an AR, and even cheaper .22LR rifle like a 10/22 would be pretty good, and are gentle enough for kids to shoot at the range.

I'd put a 12-gauge shotgun third, because they are very loud, have a lot of recoil, are limited in round capacity and shells are expensive relative to other types of ammo. Very effective, but not something you want to be shooting indoors. Same goes for rifles with the loudness. All guns are too loud too shoot indoors without ear protection, but with that said a 9 or 45 handgun will probably do a little less damage to your ears than a rifle or shotgun.

Always recommend the range (or your backyard, if you have mad land) because target shooting really helps change one's perception about firearms. I started shooting when I was around 12yo in the Boy Scouts during camping trips when we'd cordon off and area and set up a range and targets, so I have a different view of guns than many of my fellow city dwellers.