How do I Get an in design CC epub file into Amazon's kindle?

You really don't need to jump though all these hoops to get an InDesign book into Kindle. You most certainly don't need to export to Word and then rebuild in that terrible novice's-tool Kindle Create, not if you're a reasonably skilled ID user.

Also note that Amazon has dropped the MOBI file, so all forms of conversion to it or from it are obsolete. (And good riddance!)

Getting an InDesign layout from ID to Kindle is four basic steps, but there are little pitfalls all the way through and far too many variables.

1. Make sure you have a really clean layout, free of as many overides and local patches as possible. Use clean, unmodified styles for everything (and reduce complexity as much as you can; use one "Heading 1" and not several variants; use a few well-defined body styles, etc.) If you aren't a clean, skilled layout type — if you brought rough, local-format skills from Word or similar — you're going to have a long, hard time getting a good Kindle result.
2. Export to reflowable EPUB v3.0x. Don't use fixed pages except when your pages are all images anyway, such as a children's book or other graphics-based layout. For text, you want to use reflowable. And v3. Period. There are, unfortunately dozens of settings within this export (that build on that clean layout from step 1), and it can take some tinkering to get them right for your styles and layout.
3. Download the latest version of Kindle Previewer, and open the EPUB file with it. For simple books like novels and other layouts with mostly flowing text, few fancy bits like lists and footnotes, etc. you may be done at this point.
4. Adjust the ID styles that didn't come out the way you liked, and repeat steps 2 and 3. Note that you may have to make the ID/print version fairly ugly to get the EPUB/Kindle results you want; this is not a case where "pretty becomes pretty." In particular, images may end up very oddly positioned, even hanging off the bottom of pages.
5. And in the end, if you can't get ID style changes to reflect as desired in the preview, you're going to have to edit the EPUB's CSS file. This is the thoroughly expert mode; once you learn to access and tweak the export CSS, you can accomplish almost anything. Or at least, far far more, with far far better options and finer control, than anything you can do in any visual designer or builder, be it ID, Word, Kindle Create, Calbre or any of the other "easy" e-book creators.

Some basics that have worked for me, up to and including very complex layouts like the most complex textbook you've ever seen, include:

• Anchor all images in between relevant paragraphs.
  • With few exceptions, you have only one setting for all images in the EPUB export, with one global top/bottom spacing and one position option (left, right or center... and nothing but center really works very well).
• Any caption should be tagged as a dedicated format and be the paragraph immediately following the image anchor.
• You can use a page-break version of heads to minimize breaks between heads and following text, but by and large, "keep together" is a very difficult and unreliable process in EPUB/Kindle. Plan for flow with breaks wherever they occur based on screen size, font, font size and all other factors controlled only by the end reader.
• My preference for footnotes is to make them a small boxed paragraph, set right, immediately after the paragraph. There just aren't many other good options; having to flip to the end of the section or book seems clumsy to me.
• In the EPUB export settings, I suggest the following as starting points:
  • General
    • Version EPUB 3.0
    • Cover: use a separate, optimized image file, not a rasterization of your first page.
    • TOC: Multi-level, Default
    • Order: based on page layout
  • Text
    • Remove forced line breaks is a good idea; you shouldn't be using them in a "clean" layout.
    • Place footnotes after paragraph, and define an appropriate format to make them stand out/away from the body text.
    • Map to ordinary lists if you are using ID bullets and numbered lists.
  • Object
    • This gets VERY tricky if you are using images; experiment one setting at a time if these don't do what you want.
    • Uncheck all three boxes (Preserve, Use Existing, Ignore).
    • CSS size Fixed.
    • Layout: Align Center (sometimes Left might suit your layout better, but Center almost always looks/works best).
    • Space before/after: start with 10 and 10 pixels. 20 and 5 to zero works with captions but will probably need tweaking.
    • SVG: embed code.
  • Conversion settings: leave defaults (Automatic, 150 ppi).
  • HTML/CSS
    • All the real tricks are in here. If you don't know how to write CSS formats, you're going to need to learn at least the basics if you don't want to be at the mercy of the ID-Kindle handshake.
    • Generate CSS.
    • Leave page margins at zero
    • Usualy preserve overrides — but in general a clean layout shouldn't be using them.
    • Do not embed fonts. Kindle is best when left to using its own fonts. If you're doing something really arty or demanding, expect further hurdles getting text to look right in your final production, and plan to master CSS formatting.
    • And the big one... include Additional CSS. This is where you link in a CSS file that contains your own format tweaks. Doing so is the key to a truly "perfect," professional result for anything that uses more than body text and default headings.

The other settings are very advanced and don't need to be bothered with unless you really understand how Javascript is used by EPUB.

But step one — maybe step zero — is to abandon all the old, crude, novice-centric tools and methods. You're an InDesign user: it and CSS have everything you need for professional Kindle results. You don't need to go through multiple conversion, rebuilding, using Amazon's crummy tools, etc. Learn to jump these hurdles the right way, and your publication skills will take a huge leap upward. (As will your marketability!)

You might find this useful (this is the latest creator from Amazon): https://www.amazon.com/Kindle-Create/b?ie=UTF8&node=18292298011&fbclid=IwAR1KsvAseooxRnsM_wUFWWtuUdTyMQ5jXFZxGEdb7X8JIbEeIjcQU-jaQwA

Is your epub reflowable or fixed layout?