Oooh, boy, do I have some. For several years now I've been a writing teacher, then editor and publisher. I've seen an awful lot of work by aspiring writers and the exact same thing is wrong with just about every book that goes awry. The author tries to cram too much irrelevant material in the first chapter. Aunt Julie says: In your first chapter, delete all (and I mean ALL) flashbacks, digressions, and exposition. Ok, wait, I'm relenting--you may have the occasional word or even sentence of exposition. But no more. (Aunt Julie is very strict.)
So what's left in that chapter? Hopefully, an action scene that makes us fall in love with your protagonist and sets up the story, so we can see where we're headed.
Do this, my chickadees, and you shall be published! Seriously.