I could just go into the store but how do I know if I can trust their advice either or they're just trying to sell something that is stock that hasn't moved?
Since the purpose of this is home protection in the middle of the night I was thinking shotgun?
I've spent some time at a range years ago and got "comfortable" with a .40 cal handgun. But to be honest, I don't think I'd be consistent enough putting in range time so that I'd have reasonable accuracy during a crisis situation.
thoughts pro or con and/or suggestions?

Just buy a nice used Remington 1100 (they are cheap this time of year) and have it shortened to 20"
So9
Use birdshot. Buckshot will go right through a couple of drywall walls and hit someone you don't intend. At a range of a few feet birdshot is lethal.
If you nerf this up, don't bother suing me. My total worth is less than what your lawyer would charge.
A 12 gauge Mossberg 590 Mariner shotgun is my preference for a home invasion type attack. The question is availability. If you have to go somewhere to get it, you may not have time. A handgun at your side is great for immediate response until you can get to more firepower and ammo.
I'm a mossberg 500 fanatic. Have three of them. For home defense I suggest #4 goose loads in 3"magnum. The shot is large enough to do serious damage, there's more of it, and it's cheaper that 00 buck loads.
How about 12 gage ( morberg),it is good for home defense and recommend that you take someone with you that knows about guns. If you have any question freep mail myself or my husband Bottom_Gun, he is an NRA certified instructor. He is very knowlegdable about all sorts of guns. If you have a mosberg ( mr mosgerg) when the perps hear the the sound of the pump, most of the time they will think twice.
Good luck and be blessed
navygal
U.S. Repeating Arms|Winchester
Model Model 1300 Defender 8-Shot, caliber 12 gauge (comes in 20 also)
MSRP $341.00
Action: Pump Action
Stock: Synthetic Military Spec Polymer
Receiver: Black Matte
Capacity: 7+1
Safety: Cross Bolt Safety
Sights: Tru-Glo Fiber Optic Sights
Barrel Length: 18"
Overall Length: 39 1/2"
Weight: 6 3/8lbs

You can also search all makes & models at Davidson's Gallery of Guns
Good luck
But, lets get serious. In order to be prepared for a home invasion, you should be armed at all times. This just ain't practical, especially if you're gettin busy with the missus. Therefore, it would seem more effective to have a perimeter defense system in place.
I'm thinking fencing, dogs and, perhaps, Claymores.
Go with a pump shotgun with extended magazine tube (8-9 rounds) in either 12 or 20 guage (Only 20 I found was a Winchester 1300) Take 18" barrel, or 20". Put Ghost rings on it, and consider adding a forearm with a built in flashlight. Parkerized finish, synthetic stock. Best home protection weapon available. I potential user is female, or somewhat small, DEFINITELY go with the 20.
Wilson Combat Scattergun Technologies has a 12 guage that fits the bill. With all of the above, plus receiver mounted side saddle carrier for 6 extra rounds-@$1150. Without sidesaddle or light, @ $900-1100.
I'll add to the shotgun advocates. I like a 20 gauge pump. If you're lucky, the sound of you chambering a shell in the middle of the night is enough to send the intruder scurrying out the door.
I would recommend an AR-15 with a red-dot Aimpoint and Surefire light.
So what's going to keep the goblins away when you're out and about during the day? You should get a handgun to carry when you are away from the house.
Depending on what state you're in, you can probably get a CCW "permit" quite easily.
The Sears Ted Williams Model 12 ga. pump that I bought in Cincinnati in 1968 has given me years of great service, can be broken down easily in the field, and has kept quail and pheasant on my table would be my recommendation. If you can find one.
some like handguns, others like shotguns...at close range a shotgun is the most devastating weapon you can own.....in that case a 12 gauge if you can handle it or a 20 gauge is also fine with 3 inch magnum shells......many police depts use 20 gauge cause of it's ease of use.......the two best shotguns you can buy for this are either the Mossberg 500 or the Remington 870......both pump action and you need to get either the 18 or 20 inch barrels for ease of use....most military or police depts use either of these two pumps to do the job
However, to take this in a slightly different direction....

Ever heard of Magnum Research (the folks who make the Desert Eagle)? They have a revolver they call the "BFR." They insist that it stands for Biggest Finest Revolver. Really.
Here's a chance to mix your metaphors, so to speak.
The one in the picture is their BFR .45 Long Colt/.410 Revolver. Put in two or three 410 shot shells with bird shot up to buck shot type loads, then have the last couple of rounds be .45 long colt. By that time the bad guys are either on top of you or trying to get distance. In either case the bullet would have advantages by then, if you have to go that long in combat.
Of course, I'd still keep a conventional shotgun available. If you go beyond the 5 shots in the BFR you're in a serious firefight and you DON'T want to take time to reload a wheelgun without a speed loader!
More seriously, look at "less than lethal" shotgun ammo from several companies, among them Blammo Ammo. They have some very interesting loads for 12 gauge that will scare the hell out of the perps (and kill them if they're close enough). Dragon's Breath is one of my favorites, particularly at night. 90 feet of flame. If the sucker is still coming after you let that off then he means to kill you and the slug in the next shell is automatically justified.
Finally, both seriously and realistically pick a pump shotgun, either Mossberg 5XX, Remington 870, Ithaca 37 or Winchester 1300 would all be fine (I listed them in personal preference, but I have NO expertise). Then it makes sense to me to load it with successively more lethal rounds, starting with something like "rock salt" or rubber bullet loads, then bird shot, then buck shot and so on. Then practice with all of the loads you might need to use and have everyone else in your household practice with it and be 100% familiar with all of the safety and operatioin features of whatever you end up with.
Finally, with whatever you get, hopefully just the sound of you racking a pump shotgun will convince any intruder that he wants to look elsewhere.
12 ga. pump. The sound of racking the slide will turn most threats into cowards. You may never have to fire it. If you do, you can be pretty sure of hitting the target.
Benelli. Convertible semi to pump.