One of the first things I did in Julia when I started as a complete novice was to make a chloropleth map. I recall the basics being pretty straightforward. I loaded shape files with geoIO, manipulated the GeoTable a bit and used Makie to plot. I had no skill, so it must have been comparatively easy!
I’m travelling, so can’t easily offer an mwe. However, this thread may help: Scaling viz plots in GeoStats - #19 by TimG