Very Noob Question: index.html

The index.html that is in public is just a place holder. Delete that
file and add a route in routes.rb for the "/" path to point to a
controller and action you want for the default content.

I recommend getting "Agile Web Development with Rails" which starts
with a short and to the point tutorial that gets an application up and
running, then dives into more detail on each component of an