No worries, we’re here to help.
You can begin with just a Buttons Block. In the video, you can start at 1:42. Just follow the instructions there, and apply it to anywhere you prefer.
For instance, you can add that in the Footer Widget through Appearance > Widgets. If you want it at the Top Bar, you can simply add a GB Buttons Block through Appearance > Widgets as well.
No need for a new Header.