Keep the scattergun for chasing evil doers off the porch.
The MOST important thing to know about defending yourself in your home is to be able to hit the target quickly with multiple rounds regardless of the gun you are using. Handguns with hollow points are the best IMO for inside home defense. Shotguns have their purpose but even with an 18” barrel, the pattern does not open up sufficiently to be just a point and shoot weapon. Across a 15 foot room, 00 will open up about 8 inches. Of course, just racking the weapon may be enough to send them on their way while a hand gun may not have that fear factor.
Vince