AZ told you the facts. One is well armed for self defense and utility/hunting shooting with a 12ga. shotgun, and a .357 revolver.
There are options and details however, which should be considered, but still, the basic package remains sound.
Pump shotguns are generally favored by many these days, and are good, especially the Remington 870 Wingmaster. You are not unarmed with a double barrel shotgun...especially a "side by side," especially with double triggers. For fast and serious survival work, under bad conditions, this is a good way to go, even though pumps have a big magazine. Alaskan and African sportsmen notice the reliability of the double mechanism, and by the way, it is easily capable of firing BOTH barrels in a real pinch. ALWAYS try to purchase a 3" magnum if you can though, as it's all the ammo you may come across later, and it is more "powerful" (has a heavier payload) than the standard fare.
This is also true of the .38 MAGNUM, we may call it. You may favor .38 Special +P loads, but if you want to shoot or find only Magnums...they work. There may be obstructive leading in the chambers if you use .38 LEAD, though, so in that case stick to Jacketed bullets. Anyway, a DOUBLE ACTION (trigger cocker) REVOLVER is your very best choice if you are new to shooting....or then a famously reliable automatic like the 1911 Colt, and Browning High Power, I personally believe. There are many good automatics around, but they are not as simple, powerful usually, and reliable certainly as a premium revolver. Oh yes, the fierce and brutal he-man's .44 MAGNUM is a wonderful, reasonable, useful, versatile, and effective choice...especially if venomous SNAKES may be present. They also, like the .357, take shorter and less powerful Specials too...which is pretty close to the real handgun specs. which "won the West," and still works, by the way.
A good military-style rifle is always great to have, and REMEMBER...a handgun is what you use to fight your way to your long arm...which you should not have put down to begin with. Think of a handgun as something additional to have on your person, while you are working with your "real" gun, and getting the job done, no fooling around.
Semiautomatic pistols are essentially used for emergency personal defense, and especially if multiple threats are present. They may help a lot, but to really get the job done swiftly, and with the least training and "luck," the shotgun rules. Try to get one with interchangeable barrels, or a 20" or so barrel, hopefully with Choke tubes, so that you can better hit distant targets w/FULL, and closer, wider patterns w/CYLINDER bore size. Also remember that a Pump or Auto has a LONGER receiver, and therefore longer overall length than a Double with the same barrel length. barrel length is IMPORTANT, and should always be, whatever the gun type, as long as you can use well in the situation, for many reasons. You may also be able to legally fit a pistol grip to your shotgun and/or rifle. They can help a lot, and bridge the gap to the handgun quite well.
I'm of the opinion that if this individual is gonna stash it in the attic till he needs it he don't need one.....
The use of a firearm is a martial art and martial arts require practice to master or even become proficent at the very basic level.
To purchase and discover, when ya "need" it, when you first try and fire it ya have ....a warranty problem, bad ammo, wrong ammo , grease or a cardboard anti rust widget etc etc is just plain wrong.
The guy needs to heed the evacuation warnings when such threatens his door step if such is his plan.
That said if such is still on their agenda give em a ruger 10-22 with 25 round magazines from butler creek and a brick of stingers. Better to hit a lot than miss the few.....
Besides I really like the way the IDF applies their kneecapping theory to the PLO rockchuckers ! A little 6-24X Tasco Scope on the little ruger is fine medicine for the novice to start with......only hits count concept at work.