Hello Childress, and welcome,
PDFs can be a pain, but the most important thing is to check that you've got text-based PDFs and not just a scanned image.
Can you open the PDF in Acrobat Reader and select all the text, and copy it into Notepad? If so, then you should be OK in Monarch.
If you'd like to email me a sample PDF I'll happily build you a model to help you get started.
Olly is correct, determine if it's a scan image first, which it sounds like it is. Also, keep in mind there is a limit on how many PDFs can be opened at once. In 10.5 I think it was around 300 or so, I don't recall the exact number, nor do I know if the limit has been adjusted for v11.
If it's a scannned image you could also use an OCR software to convert from a scanned image to document Monarch can read.