Putting this here because it’s generic info and I may not be able to see your DMs….

Can’t help with the ghost, but I’ve self-published children’s picture books, non-fiction, and collections of microfiction.

The biggest warning with self pub is to stay away from the vanity press/hybrid press. They are not your friend. Might as well pay for the editing and cover art yourself because you have to do all the marketing and promotion yourself as well, no matter what their package says.

Traditional publishing usually means getting an agent, though there were a few who still had a slush pile (non-agent submissions), at least in the fantasy/sci-fi genres which was my interest.

Since you mentioned a ghost, be sure to have a written, signed contract before you start that outlines all deadlines, revisions, who’s in charge of implementing edits, and how all royalties are handled for all media (print, ebook, audio, game, etc. domestic and international). Even if it’s just work for hire, a written, signed, contract, ideally reviewed by a lawyer.

Depending on the content, there are genre-specific organizations that can have a lot of great info on their websites, such as SFWA for fantasy and science fiction writers.

Publishing a book can be a huge deal, depending what your goals are. Best to be clear what you want out of this before you start. Good luck!