RStudio is an editior and integrated development environment (IDE) for the R programming language. The software is open source and may be used freely.
More information about the software can be found at the project website www.rstudio.com.
Please also see https://en.wikipedia.org/wiki/R_(programming_language).
If you are using another computer, you can download the installation files at www.rstudio.com/products/rstudio/download/.
For questions about the software itself, please contact your teacher or the project support at https://support.rstudio.com.