Some good advice and some total BS (e.g. don't get a 9mm they go straight through people, get a 10mm instead

)
Forget about one shot stops, they are a myth. ALL handgun rounds are by their nature under-powered. There is an old saying about only using your
handgun to fight your way to your long gun.
Revolvers are easy to use, and you could certainly do a lot worse than a good old Smith & Wesson Model 10 with a 4 inch barrel in .38 Special.
Based on volume of sales, Glocks are the most popular self defence handgun in the USA. They are simple and reliable, but in my opinion are not an
ideal choice for a novice shooter because of their trigger configuration. Yes, I'm one of those people who thinks that Glocks go bang a little too
easily.
Having said that, a Glock 17 would make a superb home defence weapon if you are prepared to spend some time becoming proficient (and safe) with it,
but make sure you get the factory original FML (metal lined) drop free standard capacity magazines. The neutered 10 round magazines have all but
disappeared, but there are some out there still being sold to unsuspecting buyers.
Personally, I would only look at 9mm automatics unless you feel strongly for a wheel gun (revolver). They have mild recoil and practice ammunition is
cheap (buy the Winchester White Box 100 round packs from Walmart), double stack guns also offer high capacity, and with the right ammunition offer
every bit as much in the way of terminal ballistics (ripping holes in people) as the more demanding .40S&W and .45ACP.
Personal recommendations - H&K USP compact, H&K P2000 full size (not the SK), SiG P226, SiG P228, SiG P239, Glock 17, Glock 19.
Next - ammunition, I've covered what you should use for practice, now let's consider personal defence. You should go with a high quality Jacketed
Hollow Point (JHP) in a +P (higher pressure) loading. Arguably the best load out there right now is........the Winchester Ranger T 127 grain +P+
(check out my screen name), failing that the NYPD's standard load is also a superb performer (Speer Gold Dot 124gr +P) both are a little more
difficult to find but can be had from on line resources. There are other good loadings, even in standard pressure, but if you can get one of these 2,
you have the best out there based on actual shootings.
One final thought - I'm calling BS on the guy who claims to have not one but two Beretta PX4s, those guns are not currently available for civilian
sale. If he can supply the name and address of a gun store that carries them, I'll apologize - otherwise I'm calling him a BS artist (I got one for
the wife's purse

)