Ruby naming conventions?
The Ruby Style Guide is a public effort to recommend consistent conventions and best practices to Ruby developers. You should check it out.
In brief
The camel case for classes and modules definition we use CamelCase
The snake case for files, variables and methods: snake_case
The syntax highlighting in your text editor can give you some good clues as you're learning a language and trying to develop an instinct for its conventions, enforced and otherwise. I use the Linux Gedit editor.
Yesterday I was pleasantly surprised to find that some of the conventions for commenting recommended by The Ruby Style Guide https://github.com/bbatsov/ruby-style-guide, such as # TODO and # FIXME, show up as bold face bright yellow. Constant names with ALL CAPS are bold cyan. Of course, different editors use different color schemes.