It's possible to import a PDF, provided that the vectors are embedded into the PDF and not just rasterized. The PDF you attached to one of your replies shows that it does have embedded vectors.
However, opening the PDF in something like Inkscape, we can see that every single line in this drawing is its own path.
In other words, there's nothing in the PDF to differentiate letter from a single dash in the line around the toilet seat. Additionally, many of the lines of supposedly "closed" areas are actually comprised of disparate paths, so very few of the "areas" on this PDF can actually be treated as polygons.
ArcGIS Pro can work with CAD files directly a lot better than anything coming via a PDF. If you don't have access to the CAD file directly, you're probably better off importing the PDF as an image and georeferencing it, then tracing features off, as @AdrianWelsh suggests.
- Josh Carlson
Kendall County GIS