create ebook for amazon

There are about 15 or more formats for ebooks.  Many online sites will assist or do conversions, and can be seen by searching for "ebook formats and conversions"

A publisher can also do this for you if they decide to publish your work.  
An example...
http://www.pagepublishing.com/services-view/conversion-to-ebook-formats/

Is this what you're looking for, or do you need more info on Adobe and PDFs?

I'm working on a book that I plan to publish at Amazon's Kindle Direct Publishing (KDP). Here are the formats that KDP accepts:

Word (DOC or DOCX)
HTML (ZIP, HTM, or HTML)
MOBI (MOBI)
ePub (EPUB)
Rich Text Format (RTF)
Plain Text (TXT)
Adobe PDF (PDF)

The above list may change from time to time, so check out the current list at:
https://kdp.amazon.com/help?topicId=A2GF0UFHIYG9VQ

Also, KDP has an EpubCheck tool that validates EPUB files:
https://github.com/IDPF/epubcheck

And here's a link to a simple, helpful guide for building a KDP book:
https://kdp.amazon.com/help?topicId=A17W8UM0MMSQX6

Good luck with your book! Regards, Joe

Word (DOC or DOCX)
HTML (ZIP, HTM, or HTML)
MOBI (MOBI)
ePub (EPUB)
Rich Text Format (RTF)
Plain Text (TXT)
Adobe PDF (PDF)

so can I create an amazon account and a simple txt file and sell it on amazon

Thanks

You're welcome. Good luck with your book!