Exactly.

Get one with as much tube capacity as you can. My defense shotty is a 20" Mossberg 590 with the 7/8 round tube. That will handle nearly any situation 50yds/m and closer very authoritatively.

Shotguns, especially pump actions need much more training than you expect. It is NOT intuitive to load them. It is NOT intuitive to be able to shoot them quickly and accurately. And yes, you must aim. This isn't a movie and buckshot doesn't take out a whole hallway full of bad guys in one shot 🙄