To get your free domain, you need to have a valid university email. Go to: nc.me to redeem a custom .me domain.
To sign up for Github, go to: github.com/
To download Github Desktop, go to: desktop.github.com/
After you enter your custom domain name in the settings section, you’ll probably have to wait a few hours for the DNS changes to propagate. Check the status of your website using dnschecker.org and anonymouse.org/vip.html