Remember that The Gunslinger is a more of a collection of stories written over time than a single narrative, so that is why it can feel disjointed. It is pretty different from the rest of the saga too, serving as more of a prologue.
Oh I don't mean it narratively, but how the world is constructed I find it quite confusing - like, it has many temporal elements I dunno if it's set circa 1800s or 1950s.
The setting is basically Western (as in, The Good, The Bad, and The Ugly etc), but with supernatural/magical elements. Plus, there is really advanced technology lying around.
The history and background of the universe they're in is never given to you other than in fragments, because, as you will have seen, that universe's society has completely broken down. Almost all knowledge of the past is lost. The characters will encounter things and their origins are never explained in detail, if you are told anything at all. It's one of the best things about the series. Whereas a lot of fantasies get a bit encyclopedic, as the author wants to impart this massive detailed world they've created, the Dark Tower universe is very mysterious.
If you like that first section of Dracula, check out Nosferatu, the old 1921 silent film adaptation. It has old corny silent film acting, but because of the dusty old footage and atmosphere, it manages to be very creepy still, and from memory, it focuses mostly on that first part of the book.