Speaking of Flat Earths, here is a database of them: https://spatialreference.org/

You can find many flat earths, some in meters and some in feet for those of us who are still lagging behind on that front (thanks Brits)

For any who want to get into GIS, (especially using Open Source tools like QGIS) its helpful to start to remember commonly used SRIDs, or Spatial Reference IDs. A very common one I use is the code for "NAD83 / California zone 5 (ftUS)", which ID is 2229, covering the area of LA, my native Kern County, as well as a couple of other counties.