Study up on the laws & regulations in your state, county, municipality. In Florida (Palm Beach county specifically) it used to be you would go to jail if you shoot a criminal unless you were in iminent danger & have witnesses testify to that effect - even if the perp was IN YOUR HOUSE! Thank God that has changed! Imagine. Somebody breaks into your house, starts hunting through, destroying, stealing, all your stuff, drinkin' your beers, eating your food, beating and/or killing your pets, and if he's not directly threatening you, there's nothing you can do but wait for the cops. I called it the 'Dead men tell no tales' law.
Now as for guns, don't cheap out. Smith & Wesson, Glock come to mind right away. Generally in your price range & good names/reliability. I still have a S&W Model 469 9mm that has over 5000 rounds through it, and it has never jammed - Not once with any brand of ammo I've ever tried. You will be betting your life on the weapon, so be sure it is totally reliable, and keep it maintained. Mine gets cleaned, oiled, & polished regularly whether it's been used or not.
Find a gun from a reliable maker that fits your hand well, that you're comfortable with, even if it is a smaller caliber like a 380 auto - which is only slightly smaller than the 9mm. Some folks love those big bore 40 S&Ws or 45ACPs, but if you're afraid to fire the thing or can't control it, it's nearly useless. Bad guys typically run like rabbits when they hear the crack of gunfire - no matter what caliber ('cept maybe a 22
).
#1 rule, if you have a weapon handy, be prepared to use it or have it used on you. Once it is accessable, it is all or nothing to the guy on the other side of the barrel, so if you're not ready to use it, consider yourself dead.
#1 rule, NEVER point the gun at anything you don't intend to destroy/kill.
Both #1 rules for a reason.
