Go back to Settings in your Dashboard, and click on General. In the field for Site Title type Van's Surfboard Sales and Rentals and for the Tagline put The Coolest Spot in Miami Beach than click Save Changes.
After you refresh your site you will see that the Site Title and the Tagline in your header had changed. Also the tab in your browser had changed as well.
Next you are going to adjust the Layout Settings of the theme.