Is there a way of saving only a single drawing from a file containing multiple drawings to a PDF file?

In Model Space, Create View of the separate drawings you want to print and insert the Viewport into Paper space.
Make any adjustments or additions.
Set up the Page Setup for the paper and orientation you want to use and Go to the Print Menu.
Set printer to PDF995 or Adobe PDF whichever you have and then Print.
You will find that a PDF page comes up with your drawing which you may then save and print.
You may repeat this for any other drawing or part drawing by creating a view and if necessary extra Paper Space pages.
This technique is common to all printing methods. You create in Model space and choose the views to print in paper space