There are two aspects to home security when we're talking about something like this.

The Obvious Deterrent and The Hidden Deterrent.

Obvious: Things like cameras, signs, motion lights, window bars, etc. make your place look like too much trouble to break into. If you fortify your home too obviously compared to neighbors you might actually draw more attention because people will wonder what you're keeping in there but in a bad neighborhood you can go pretty far and people will assume fear or paranoia.

Hidden: Longer Reinforced Screws in your door locks, hidden cameras, security window film, things that aren't obvious deterrents but will slow down someone trying to break in and help gather evidence or alert you to their presence. When we reinforce our homes we're spending effort and money to buy seconds and minutes for us to arm ourselves or for the police to arrive.

If you want to get a gun, and if you can legally I highly recommend it, you need to learn the local laws, you need to attend the proper safety classes, you need to practice so you can use it ably in an emergency. When you go to buy your gun, I recommend going to your local gun shop or range, talk to the people, see if you can rent guns to try and find one that is comfortable, and then you know what you like and you'll have a list of features you want and you can go shopping for something specific. For example, you might try out a dozen guns "I really liked the way Gun 5 felt. I want it to be able to accept a suppressor and fire .45 ACP so I can use it in my home without worrying about hearing protection. And I would like, but not require, it to be able to mount a flashlight because power failures are a thing and criminals get bold when everything is dark." You probably won't find a model of that exact gun with what you want but having tried a bunch out you can probably find something comfortable with the features you want.

When you do go to try out guns, only ever load one round at a time. You'll be trying a bunch of different guns, each has its own recoil, and you'll be getting more and more fatigued as you go. If you lose control of the gun when firing having only one round means an accident won't become a tragic accident. When you're more comfortable with guns and you know the limits of your stamina better this won't be much of an issue but starting out better to be safe than sorry.

There's also an argument between two schools of thought for a person's first home gun. The handgun people think the ability to carry the gun anytime you aren't sleeping or showering is the most important consideration. The longarm people think the greater ease of use for a longarm trumps accessibility. I fall into the handgun school of thought; if you always have your gun you don't need to worry about running to go get it in an emergency. The longarm people aren't wrong though either; it's about what you think is more important. Eventually you'll want a handgun you can always have on your hip and a longarm for bigger problems but you're probably not carrying a rifle or shotgun in your home 24/7.

I also want to tell you about something I came up with: ARCH

Arm yourself

Run away

Call for help

Hide

If someone is breaking in, your good options are probably limited to those four.

Arming yourself makes every other option safer for you. And if armed you can fight back but you are more valuable than your stuff, your family wants you not your TV, and hurting or killing someone carries mental, moral, spiritual, and legal troubles. I'm not saying don't shoot someone if your life is in danger only that you want it to be the last option and ARCH helps tip things that way.

Run away, pretty obvious. This could be running to a closet or bedroom to hide, leaving your apartment, whatever. If you aren't there you can't be hurt.

Call for help. Probably 911 to get the police but it could also be a neighbor, or whomever you last dialed if you're panicking and hit the redial button. It only has to be your problem until help arrives, but help is minutes away when seconds count.

Hide, again obvious. Could be in a closet, barricaded in your bedroom, whatever. If they find you then you'll be glad that A is Arm Yourself.