Ruby/Rails - How can I create a 'Treehouse like' website, using Ruby on Rails? (need some guidance / resources)

Hello all,

I need some guidance in creating a website on Ruby on Rails. I want to create a website just like treehouse (a bit more simplified though) for Math and English. I tried creating this with WordPress and though it works, I feel that it is very hacky and clunky and conforming WordPress to this also not ideal. I like WordPress because it's easy to manage content on the website and lots of features are pre-built for you but I feel like it a) not secure whatsoever. b) it's probably good for a couple thousand users but I'm not sure if you can build a web app on WordPress that can scale for a few hundred thousand users.

Overview:

Users will have profiles, and there are courses > chapters > lessons in which users can take. Users earn badges after completing a chapter and will earn points when doing certain things on the website.

I need a backend in which the non-technical people creating the website's content can easily manage it and add/edit/ delete courses, chapters, lessons, pages, etc, such like WordPress (although I'm not sure how WordPress can be integrated with RoR, JSON maybe?

I'm currently on the Ruby track and I'm 2/3 of the way through it and I seem to feel a little lost when thinking about my project.

What do I need to include in this Rails app? I know I will need certain gems like devise and simple form. But what else will I need to get this RoR project started?

Any recommendations on what I should read up on or courses I should take (other than the ones here on treehouse)?

Any help would be greatly appreciated!