Start writing your own content or edit the current to fit your needs. To create, edit or remove content you need to login to the admin panel with the username `admin` and the password you set in the installation process.
Your About page is typically one of the most visited pages on your site, need to be simple with a few key things, such as your name, who are you, how can contact you, a small story, etc.
Update the settings of your site from the admin panel, you can change the title, description and the social networks from Settings > General.