The sf package is rapidly developing, and so it is worthwhile to seek out the latest
help guides and tutorials to learn more about the system, particularly if you are doing
this a while after the spring 2019 workshop.
The package authors have created a website with more on the package. They also have a book called Geocomputation with R, which is currently available online and will be available in print sometime in 2019.
Both these sources go in depth to describe the sf package and how to use it. If you want
other examples of using the package, many people have recently written blog posts with examples
of using it, so it’s worth googling something like “blog post map r sf”. Finally, some of the
ggplot references listed in the “Plot” section’s “Learn More” include sections on mapping.
There’s an article on the
tigris package, if you’d like to find out more about how to use that package to read in
US Census spatial data.