Face it girls. Men are bigger than you are. They are taller, heavier, and stronger that you are. If you have a long walk to your car after dark, or to your apartment, you ought to think about carrying a gun. “All people were NOT created equal; Sam Colt made them that way.”
You are thinking about a hand gun that can be concealed in a purse, a pocket, a holster, a car glove compartment, a desk drawer, wherever. Hand guns come in two flavors, revolvers and automatic pistols. I recommend revolvers because they are extremely reliable. Pull the trigger and a revolver always goes bang. Automatic pistols not so much.
Handguns are made to shoot a variety of cartridges (bullets) ranging from target practice rounds that would not kill a flea up thru Dirty Harry’s 44 Magnum (“The most powerful handgun on the planet”). You want the most powerful round that you can shoot well. For many people 38 Special is easy to shoot and powerful enough to do the job. The more powerful the round, the worse the recoil and the louder the report. You want the go to a shooting range and actually fire the round you are thinking about and see how hard it is to shoot. While you are at the range see how well the gun fits your hand. I learned to shoot in the Air Force where the issue revolver was a miserable to shoot 38 special. The trigger was too heavy, the grip was not big enough to get all my fingers around it, and the wooden grips had been soaked in gun oil for 20 years and were slippery. The gun twisted in my hand after each shot. Later I acquired an Army .45 and it shot like a dream. Try to shoot a number of different guns, you may find one that shoots better for you than the others.
Two things about shooting. Always wear ear defenders, those bulky plastic earmuffs, ESPECIALLY on an indoor gun range. Without ear defenders the report is so loud that it can scare you into a permanent flinch, where in you squeeze the trigger too fast and too hard and miss the target. The other thing is to shoot a hand gun with BOTH hands. This is the Weaver technique which became standard in the late 1960’s and it improved my shooting a lot.
You need to get out and shoot your gun for practice if you expect to hit anything for real. Squeeze the trigger gently so that it is something of a surprised when the gun actually fires. Line up the front and back sight over the target bulls eye. Take a small breath and they hold it while you line up the sights and squeeze the trigger. When you get home from the range clean your gun, especially the inside of the barrel and cylinder. Wrap your gun in an oily rag when you put it away to prevent rust.