Your PDF is a scanned paper drawing. Inkscape doesn’t convert that to vector lines. SketchUp Mac can import the PDF directly as a raster image. With a PC you would have to save it as an image from a PDF editor.
What are you trying to accomplish? There are ways to convert raster lines to vector–you can even find some online converters for that. If you are just interested in getting the property lines for the lot indicated, there are some extensions that can do that. There’s at least one in the Extension Warehouse. I have an ancient one that I used for the following although it doesn’t seem to be available anymore.