Hello, i'm a complete newb at R (just downloaded it for the first time today). Here is my problem: I tried to fix something and changed the initial working directory (under preferences and startup) to a folder on my desktop - and I think that is causing me some problems, now that I want to install packages and unload them. I just generally feel like I shouldn't have changed it, and now it seems impossible to just make the settings under preferences go back to the default, like when I installed the program for the first time. I have tried uninstalling R, but when I reinstall it has remembered the initial working directory - even though I used this command in terminal (which I found in https://cran.r-project.org/doc/manuals/r-release/R-admin.html#Uninstalling-under-macOS):
sudo rm -Rf /Library/Frameworks/R.framework /Applications/R.app \
/usr/local/bin/R /usr/local/bin/Rscript
I just want to be able to have a completely fresh start with R and Rstudio 
Is this poosible and can anyone guide me how to do this?