A lot of people worldbuild when they daydream and have the bones of a story kicking around in their brain, but have to pay the bills and raise the kids etc so they never flesh it out and write it down. What’s your story’s premise? Fantasy, sci-fi, alternate history, mystery, western, whatever genre.
There’s something good here - if anyone takes this up leave a link or something for us other folks to check out, too.
The first thing that comes to mind when thinking about fleshing this out: who/what made the train station? Given it’s a place people stay only for a short amount of time before being whisked off to their afterlife, what does the MC learn staying there for so much longer?