Swirl is a great and easy way to get you started with R. Install and open it by clicking the green arrow on the right.
Install Swirl Package:
install.packages("swirl") library("swirl") swirl()
Once you enter your username, it prompts you to choose a course to install. Choose 1 for “R Programming” to learn the basics. Then, enter 1 again and it will take you to a menu of courses you can choose from.