Those buttons are located just under the Plot tab (see figure below) You can open the plot in a new window by clicking on Zoom and export your plot by clicking on Export.
If you plotted more than one plots, you can navigate between them by clicking on the arrows. For instance, run plot(1:10) and you should see it in this tab. I discuss about the Files tab in more detail here so let’s discuss about the other tabs: The last pane (blue) is where you will find everything else such as your files, the plots, the packages, the help documentation, etc. In this pane you can also see a tab with a history of the code executed and a button to import a dataset (more on importing a dataset in RStudio). This means that you can now perform any computations with a, such that if you execute a + 1, RStudio will render 2 in the console.
