Create a new repository and use this as a template.
Name your repository with the course name you want in the address. The address will be in format https://centria.github.io/<repository>/.
Use only letters, numbers and dashes in the repository name!
In your new repository, go to SETTINGS. Scroll down to GitHub Pages and select master branch as your source. If you want to use another branch, select that instead. DO NOT CHOOSE A THEME. This template uses a remote theme and is already set up.
Your page should be ready and online. This might take a few minutes.