First step : Download R if you don't already have in your machine. You can download it from below link.

https://cran.rstudio.com/

Second step: Download R studio from below link. RStudio is a set of integrated tools designed to help you be more productive with R. It includes a console, syntax-highlighting editor that supports direct code execution, as well as tools for plotting, history, debugging and workspace management.

https://www.rstudio.com/products/rstudio/download/

Once your machine is prepared watch below 3 videos published by David Langer. He did a very good job in explaining R for the purpose of Data Analysis.

Its good to have some basic knowledge of R before you watch these videos but not mandatory as he explained small small sections pretty well.

First Part:

Second Part:

Third Part :