Long-term, you should understand more about what you are doing. Rote clicking in RStudio may be a short-term survival method but won’t work for long.
Oh My Git! is a free and open source interactive game for learning Git. It’s very beginner friendly, using a graph to visualise the worktree. Lessons can be completed using a playing card interface in addition to the built-in command line, which is there for when users become more comfortable.
The book Pro Git is fantastic and comprehensive.
Find a powerful Git client (chapter 8) if you’d like to minimize your usage of Git from the command line.
Hadley Wickham’s book R Packages has an excellent chapter on the use of Git, GitHub, and RStudio in R package development. He covers more advanced usage, such as commit best practices, issues, branching, and pull requests.
Ten Simple Rules for Taking Advantage of Git and GitHub http://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1004947
RStudio’s guide Version Control with Git and SVN
The book Team Geek has insightful advice for the human and collaborative aspects of version control. It proposes Git strategies suited to different characteristics of teams.