Unless you plan to carry concealed or get a concealed carry license skip the pistol for your first gun.
If you want something for home defense that sits by the bed get a 20-gauge pump shotgun. I’ve never met anyone man woman or child that couldn’t shoot one and #3 or #4 buckshot is hard to miss with within 20 or 30 yards. You can go to almost any sporting goods store and pick one up for about $250. I like the Maverick 88.
If you want something to hunt with or just have in case of “troubles” get yourself a decent bolt-action rifle with a 3x9 scope in a popular caliber such as 308 or 270. Rifles are easier to shoot and you can use them for hunting. Once you shoot the rifle a few times and are comfortable with it you can put it away for those “troubles.”
If the US gets ripe enough you need to stack bodies you are going to want a rifle more than a pistol and if you have a shotgun or a rifle you can pick up a pistol, there will be plenty on those bodies you are stacking.
That’s my extremely qualified opinion, but with that said opinions are like assholes, everyone has one.
Good luck out there, be safe.
.223 or 223
2.23 is not a thing 5.56 is the metric measurement of .224 diameter bullets which are used in both 5.56x45mm and .223.
To go deeper, a civilian .223 Remington is almost identical to the military 5.56x45mm. Both use a bullet diameter of .224 and a weight between 40 grains and 77 grains. The differences without getting super technical are in SAAMI pressures. A .223 Remington cartridge produces less pressure than the military 5.56x45mm. You can shoot both out of a rifle marked 5.56x55mm or .223 Wylde but it is not recommended that you shoot 5.56x45mm in a rifle marked .223 Remington.
.223 Remington (SAAMI MAP): 55,000 psi (≈379.2 MPa) maximum average pressure (piezo).
5.56×45 mm NATO (NATO/EPVAT service pressure): ≈ 62,366 psi (≈ 430 MPa) service pressure (piezo).