Depending on how the PDF was produced, there are tools, such as FME, that can extract vector data from PDF. You would have to find a way to georeference then write to your Indoors schema. However, you could also digitize directly to your indoors schema but you would have to manually supply all of the required indoors schema attribute values for every feature. Once you have base floor plan data in the Indoors schema, I think you could then use the geoprocessing tools to start creating your routing network and additional feature classes such as people, events and other operational feature classes you might need.
Hope this helps!
