Because there may be times you want to work off line, you should also install R and RStudio desktop if you have access to administrator rights for your local computer. You will need to download and install both R and RStudio. Although you can go to the R Project website and install R from there, you can also go directly to the RStudio webpage and get links to install both R and RStudio.
Here is the link to the R Project website: http://www.r-project.org
I suggest using the RStudio website to get both R and RStudio.
The RStudio website is: http://www.rstudio.com This site will give you plenty of background information about RStudio, but you can get lost in the many options. We are going to use the free - repeat free - desktop version.
This link should take you to a page where you can find download links for various types of computers. https://www.rstudio.com/products/rstudio/download/#download
Here is a 4-minute video on installing R and RStudio on your desktop: