skruft

I have both and find just a little recoil difference but I'm not sensitive. I guess I would say that pumps are a little cheaper and require more skill to get the second shot off. I have no shotgun that has ever misfired (lucky maybe!)so don't think there is a real reliability issue from one to another type.

I think the gun you bought will be just fine for all your purposes.

I think the other folks have answered your question well. About the only other things I can think of that are basic to me but that you don't critically need to start are a bag of the right size to carry extra targets (such as one of the canvas bags you see being used on boats) and something to use to see where you are hitting. A spotting telescope of the right size is the best for this last, but for many years I used a small pair of Nikon compact binoculars that were perfectly good out to 25 yards or so. If your pistol has adjustable sights you need the proper tool to adjust them. A small staple gun is best to put targets up. Be sure you bring staples too. Also I always suggest to people that they get a large range bag, not a small one. Nothing is so useful when you start to carry more stuff to the range.

I don't think this ammo is much good from an accuracy standpoint, but when I shot one of those 525 round boxes I don't think I had any misfires.

I agree it is very dependent on the firearm and its use. Still I think it would be difficult for anyone except a world-class competitor to wear out a quality firearm beyond repair in anything like normal use. Glock pistols have been tested for almost unlimited numbers of rounds. Very fine "best London" shotguns go through hundreds of thousands of rounds and last literally for centuries. On the other hand many guns have small parts fail after many rounds, so that they need some kind of repair. Competition high power rifles are often rebarreled long before an average shooter would see anything wrong.