Another vote for Airsoft
I'll agree on the whole Airsoft issue for a variety or reasons:
1) Airsoft 6mm plastic pellets are pretty darn cheap
2) Though it is possible to hurt somone with an airsoft gun, unless you hit them in the eye or chip a tooth it's relatively unlikely. Less likely to damage the house too. Not telling you to shoot things you shouldn't shoot, just saying the consequences are slightly less dire.
3) Airsoft airguns come in far, far cooler and more realistic versions than other airguns. Full-size visually-exact replicas of hundreds of firearms are available in Airsoft version. Airsoft Glocks, Colts, Sigs, all close resembling their real-life counterparts in look, feel, and handling.
4) Around $20 or so will get you a spring-powered Airsoft, where you rack the slide by hand to load each shot. A bit more cash will buy you an Airsoft that cycles itself either through battery power of with a "green gas" propellant sold at hobby shops and online.
5) A gentleman named Tatsuya Sakai won the 2004 Steel Challenge, an American handgun competition. Since Tatsuya lives in Japan, where civilian handguns are forbidden, he trained throughout the year with Airsoft, then arrived in the States a few months before the competition to get adjusted to using a real handgun. Food for thought...
So, if you're planning to hunt or engage in formal Olympic-type target shooting, a good-quality pellet gun would be the way to go.
But if I guess right, I figure you just want to have fun with a shooting-piece that works and feels like a real firearm. In that case, I'd check out the Airsoft options sold on
www.gunbroker.com, Ebay, etc. Find one of good quality that resembles the kind of pistol you want to get after you move out of the house, and let the learning process begin. There are zillions of reviews written up on the web for various models and manufacturers of Airsoft, so plenty of places to read up on the subject.
Lots of good THR discussion on Airsoft and its use as a training tool, just click the "search" button at the top right of this webpage.
Good luck on starting out in the gun world, -MV