In this video Guil uses a folder called "Public" which also has an index.html file in it. Also, great tutor!

The index.html in the src folder is the one that Guil copied over from his project assets to build the App Component, and the index.html in the public folder is the one that is actually being loaded onto the page. The index.js file, in turn, loads the App Component into the DOM via the #root div in the public folder's index.html.

If you're still getting a handle on React, I think it's really difficult to work with create-react-app. While it does so much of the behind-the-scenes work for you, you're at a disadvantage trying to manipulate all the templates without understanding how the whole thing is put together. I'd highly recommend checking out The Net Ninja's React playlist on YouTube, he's amazingly talented at being both concise and thorough in his explanations. I followed along with that whole playlist between Guil's Create React App course and this one, and while I had to do some extra legwork to get everything to work with ES6, he explains the concepts so well that I feel much more confident now.