how to change page size, add drop caps before publishing paperback

[RatherBWriting]

I have Adobe Acrobat Pro, version 2023.003.20284.  I have imported a pdf file into Adobe Acrobat Pro and need to make sure that the pages are set to 6"X9".  I also want to add a drop cap letter to the beginning of every chapter.  This will be a paperback book; it will be uploaded for publication, so it needs to be right.

How do I do these two simple things, set the page size and add a drop cap letter to the first paragraph of each chapter?  

This software is anything but intuitive!  I changed back to the "old" version, which is easier to navigate, but even that does not present these simple options in amy obvious way.  

Thanks in advance -

RatherBWriting

[try67]

This is not something you would do in a PDF file. It needs to be done in the original file used to create the PDF, like InDesign or Word.

[RatherBWriting]

I didn't know that!  Unfortunately, I made the questionable decision to not update my Word document as I made changes here and there in my epub.
Would it be better to change the epub back into a Word document, or to change the pdf back into a Word document?  Then I'll make my changes and create a new pdf file out of the completed Word document. 

thanks!  I appreciate your help. 

RatherBWriting