Install R Runtime
Installing the R runtime is reasonably easy. Go to the official R project website here:
Then find the "download" link. There should be a link towards the top of the page.
You will then be asked to "select a mirror". A mirror is a website that contains copies ("mirrors") of files. The listed mirror sites all contains copies of the R runtime installation files. By choosing a mirror closer to you geographically, your R download will proceed faster.
When you have chosen a mirror (clicked on a mirror link), the mirror site will ask you if you want to download R for Linux, Mac or Windows. Choose the installation that matches the operating system your computer runs.
When you have downloaded the R runtime just install it like any other application.
After installation you whould be able to run R from the command prompt of your computer. If you are working with a graphical user interface, you might prefer installing R Studio and work with R within that. I prefer that whenever possible.