Thank you for the incredibly kind review!
Also, yeah, the PDF counts the cover as the first page, so the PDF's page count will always be one off from the actual page count.
Adjusting page numbers is definitely possible within the PDF format. I don't know if this is helpful (I make my PDFs by exporting from a Word/Writer documents, so for me it wouldn't be,) but here's a wikiHow article about it:
https://www.wikihow.com/Renumber-a-PDF-Document
(The article is, sadly, for using Adobe Acrobat Pro)