How do I get PDF's to send and receive as PDF's and not the entire PDF printed out.

If you attach a single-page PDF to an outgoing Apple Mail message, it will appear not as an icon, but as a full PDF page. You can fix that by right-clicking on that PDF attachment and choosing View as Icon. Multi-page PDFs attach as icons. Regardless of how the PDFs are attached and appear to you, the recipient's email client will determine how they are delivered (most likely as attachment icons), and very unlikely as open documents.