I have recently written a 115 page fiction word doc although I did not format the document
in chapter margins. I basically need assistance creating an EPub with chapter margins from a word document I recently created.
I do not know what a chapter margin is, but here's the ePub guide >>
You'll want to review this article in particular for setting up your chapters:
For an EPUB file to work, it needs to use Heading Styles in Word to determine chapter locations.
I would also encourage you to look through the entire eBook creator guide (linked above in Kevin's post).