Get a real gun. Then go to a tactical trainer who has served in the military ideally in a small arms instructor capacity - they're all over the nation - and inquire about home defense courses.
And don't get a "handgun", get an AR-15 "pistol". That is, an AR-15 platform, a stabilizing brace, and a shortened barrel. If you're unsure what all this means, don't worry, your local firearms dealer will almost certainly know and understand if you come in and ask for those things. If a break-in occurs, you'll be too nervous and too frightened to aim well with your standard 9mm handgun. An AR-15 with a stabilizing brace and a shortened barrel with a vertical forward grip is sturdy, you can brace it against your shoulder (obviously), and it has sufficient power to stop an intruder.
At the end of the day, you and only you are responsible for your own safety. Even if you live in a gated community, you cannot count on your local security or law enforcement to arrive quickly enough to save you. Remember the old adage. "When seconds count, the police are only minutes away."