Start out with the
Kindle Format 8 Overview page at Amazon.com. Download and read the publishing guide and download and examine the sample books.
You can force page breaks in HTML (and thus KF8) for reflowable text, but if the reader increases the font size it might break at the wrong place. Nonetheless, it is doable. A better option might be to use Kindle Panel Views as illustrated in comics and graphic novels.
Again, everything to get you started is on the linked page referenced above.
BTW, welcome to MobileRead! A better place for this kind of question is probably the mobi forum here at MobileRead:
https://www.mobileread.com/forums/forumdisplay.php?f=168