if you are not gun people, my only recommendation is to choose a caliber and weapon that does not have a ton of recoil.
And often people are not as familiar with a semi-automatic, and working the slide is hard for some people. My recommendation is to get a Ruger LCR revolver in .327. this will go against the grain of many people here, but I don’t think I need to go against the entire zombie nation, I most likely will need to defend my home against intruders looking to steal stuff.
That Ruger revolver means you can shoot the very effective and powerful .327 cartridge, but also 32 magnum 32 regular and 32 short. You will be able to find a cartridge that you can manage without flinching. Being accurate and placing your shots is far more important than having some hand cannon that you can’t hit what you were aiming at.
Lastly, a revolver is as uncomplicated as it gets and is a reliable weapon. I’m an older guy and so I love me some wheel guns. My final suggestion would be that when you purchase them, you take them to a gun range and find out which ammo caliber and brands your gun likes and you like. When you find the right ammunition that you will be using for self protection, make sure you practice at the range with that exact ammunition. You need to be comfortable and proficient firing your gun.
Anything less than being comfortable and skilled is a danger to you and a danger to others. if you ever need to use it, you do not want to be nervous and unfamiliar with using it.
Good luck.