I like to build things. This section is some tinker projects, I have built.
Here are some useful resources for R:
https://journal.r-project.org/
https://www.jstatsoft.org/index
http://www.rdocumentation.org/
http://www.statmethods.net/input/datatypes.html
For a learning-by-doing approach try DataCamp. If you register using my link you get two days free access to all material or if you’re into more theory, try Coursera (not an affiliate link!)