Help Make an EPUB 3 of an Illustrated Reader Magnet

Google AI suggested this:

To convert your PDF into a universally compatible Fixed-Layout EPUB 3 (which fits both Amazon KDP and BookFunnel), you must use Calibre.

Here are the step-by-step instructions for a beginning self-publisher to complete this conversion process using Calibre…

Have any of you used Calibre?

Is there a better option?

Thank you!