Beginning R training materials https://mjwebster.github.io/LeapingFromExcelToR/ProsCons.html
Other sites for learning ggplot:
ggplot tutorial: http://r-statistics.co/Complete-Ggplot2-Tutorial-Part1-With-R-Code.html
That includes a masterlist of plot types (with sample code) http://r-statistics.co/Top50-Ggplot2-Visualizations-MasterList-R-Code.html
Other ggplot guidance: http://zevross.com/blog/2014/08/04/beautiful-plotting-in-r-a-ggplot2-cheatsheet-3/
ggplot extensions: http://www.ggplot2-exts.org/gallery/
Create maps in R: https://www.computerworld.com/article/3038270/create-maps-in-r-in-10-fairly-easy-steps.html
The R graph gallery: https://www.r-graph-gallery.com/
Styling your Markdown pages with KableExtra: https://haozhu233.github.io/kableExtra/awesome_table_in_html.html