You can manage your "About us" page by going to the back office > Dashboard > Settings > About us
Click on About us and you will see the page management screen. 
At the top of the page, you can choose to show/hide the About us page on your booking form via the option "Show About us page: Yes/No"
In the text field below, you can compose your About us page using the Text editor.
Don't forget to click on Save & Close when you are done to save your changes.