My react app is not loading the index.js, you can see my repository at https://github.com/Vitorrrocha/Star-Wars-info and the gh-pages: https://vitorrrocha.github.io/Star-Wars-info/ .
package.json: https://github.com/Vitorrrocha/Star-Wars-info/blob/master/package.json
Which branch are you trying to serve as a GitHub page? I see you have just a master branch.
You could make a branch called gh-pages and push your build there. I see you have gh-pages installed as a devDependency. You can use gh-pages -d build
it will do everything for you. (build is the output folder of react-scripts build.)