RStudio - A good first tutorial using a simple spreadsheet

As a complete newbie of 'R' I asked the community for a nice gentle introduction. Below are the suggestions they sent me:-

http://zevross.com/blog/2016/04/19/r-powered-web-applications-with-shiny-a-tutorial-and-cheat-sheet-with-40-example-apps/

https://github.com/rstudio/shiny-examples

http://www.open-meta.org/technology/a-totally-different-read-me-first-shiny-tutorial/

My choice for interrogating a CSV/txt file:-

http://web.cs.ucla.edu/~gulzar/rstudio/basic-tutorial.html