After learning Tableau and finishing the airline delay project, I started to learn R recently. R is a programming language software that for statistical computing and graphics. In recent years, R has increased substantially in data analysis area. Instead of learning R, I learned SAS (Statistical Analysis System) when I was in school, which is very similar to R. In my opinion, they are both very powerful and most widely used statistical software.
Here are two websites that I am using to learn and practice R: