Okay, the first post was getting too long so had to break it up! :)
So, I left off with having got nginx botted up and with everything being run off port 80. Now we are wanting to move away from the hard-coded simple Express server that I orginally build using vim on the EC2 instance, to being able to pull backend code using git to that instance.
To do that, I instantiated a repo for the backend code.