>What is R?

R is command-based. So I'd recommend you investigate R form within Rstudio. Installation of R and Rstudio is a breeze in most cases.

https://www.rstudio.com/

Beware that R is not exactly a small shop tool. It's a complex do-it-all package for "big data" specialists with a strong background - possibly acquainted within academic circles - in statistics. But it's mostly free.

Daniel.