Thanks for hanging in there with me @Sam_G 
I got it figured out.
1st: as you mentioned, Litchi needs a kml, not a shapefile.
2nd: Just keep looking! I found the county assessor’s website that showed the parcels, but there was no way to download or copy the shape or kml. After about a thousand more searches, I finally found a site where I could download the parcel kmls. Whew! Then it was a simple matter of filtering the view to only the parcel I wanted, and then downloading the kml.
So I didn’t end up having to create it, and it’s a good thing, too…the kml I downloaded for a single property is a super odd shape, and has 122 waypoints. 
Mystery solved!