Setting a different theme
The quickest and easiest way to change your theme for this is to use the default “Theme Chooser” in Github under “Settings > Github Pages” which comes with a small selection of well maintained default themes.
Configuring A Custom Domain
You can also quickly and easily change the domain of your site to a custom domain that you have purchased elsewhere.
We will not be going through this but Github has excellent documentation on managing custom domains for github pages sites.