Not sure if that helps, but if you’ve never programmed before, I definitely recommend Automate The Boring Stuff With Python by Al Sweigart. The book is free to read, plus the author is on Reddit (u/alsweigart) and releases free signups to the Udemy course based on the book each month.
Privacy versus convenience… For what I know, the most common solution to your concern would be to setup a Calibre server and access it via your Android devices. But that’s obviously a tad more complex than uploading EPUBs to Google Books.