I have not watched much anime.  I see that this is about a boy who can see ghosts/spirits.  What else can you tell me?
It's a very long running series with a very large cast of characters. It's about shinigami, or spirit reapers, who protect humans from monsters called Hollows.
How long have you been watching the show?
Since about 2005 so it's been a while.
Have you watched Attack on Titan from Amazon?
I have, I watched the first two seasons. That's also a really good show, much more mature and gory though.
Do most anime have ghouls as part of the cast?
Not most, that's only a small part of the anime industry. There are many animes, for example, called slice-of-life where it's just following normal people doing normal things like people going to school or part time grocery store workers with nothing supernatural or otherwise.
So would these be more like a sitcom?
Yeah you could say they're more like sitcoms. Depending on the specific anime it could be more like a sitcom or more like a drama.