Slide-action shotguns are reliable, fast-shooting, and simple to operate. They are, however, NOT foolproof. You can short-stroke the action, and wind up with an empty chamber. It’s possible, on some models, to double-cycle, and wind up with a nifty jam. I, personally, like pump guns, but they’re not even remotely the only choice. There are semi-autos in a number of stripes, including gas- and recoil-operated weapons, as well as single and double barrel break-action shotguns. Also others more exotic than those. A pump gun is a very good choice, IMO, but whatever you choose, training is the key.
Everyone should know what happens next… C’mon, sing it along with me!
Theme song time!
Whatever you pick, get thee to the range, and practice, practice, practice. Practice until the guys at the range know how you like your coffee. Practice until they know the sound of your car, and have your coffee waiting for you. Practice until you’re sick of it, then practice some more. Practice until your hands have minds of their own when it comes to safe, accurate, correct handling of your weapon. Practice until it points like an extension of your mind. Then practice still further. If you’re going to own a weapon for defense - Or even if you’re NOT going to use it for defense, but are planning on using it at all, for any purpose - you are responsible for the safety of everyone around you, IRT your weapon… Practice until you are worthy of that trust.
Then practice some more!