You've accidentally posted in the Forum Lounge, a non-technical support hangout for all Adobe software users.
What program are you using?
Knowing that will allow a moderator to get your post in front of people who are using the same program.
It's no accident, Jon, my friend. I've spent a fruitless hour with Adobe Support and they referred me here. I'm using Adobe Acrobat DC. Thanks for any advice someone can give me. Cheers, Art
What Jon was trying to say is that you posted in an area of the Adobe Forums that is not meant for getting help with problems. The Lounge is a "non-technical" hangout, which means that your question would have gotten lost there. Jon moved it to a more appropriate area. The next time you want to post in the Adobe Forums, please find an appropriate area, that increases the likelihood of actually getting help for your technical problems tremendously.
You mentioned that you "have no product" - that's a small problem when it comes to manipulating PDF files: In order to resize a PDF file without destroying any of the information in it, you either need Adobe Acrobat DC Pro, or any version of Adobe Acrobat with a 3rd party imposition plug-in, or a standalone imposition tool. The free Adobe Reader is not sufficient to do what you want to do.
If you have Adobe Acrobat DC Pro, you can use the preflight tool to resize your document. Your desired target size is very likely not one of the sizes it supports out of the box, so you either need to copy an existing fixup that e.g. resizes to A4 and change the target size to 6 1/8" x 9 1/4" or use the existing fixup that allows you to specify the size and then provide the target size in the units required. For a 3rd party plug-in for earlier versions of Adobe Acrobat Pro, or any version of Standard, I would recommend something like Quite Imposing. Unfortunately, I don't have any experience and therefore no recommendation for a 3rd party standalone tool.