The pages of your Fangage platform can be managed by clicking "Content" in the sidebar of your admin panel, and then clicking "Pages". You can then easily add pages to your platform, with static content like a biography or contact information - or interactive pages by embedding HTML and CSS.
After you finish creating your page, you can add them to the main menu of your platform via "Content" -> "Menus". If you add a page here, it becomes easily accessible for visitors of your platform.
Pro tip: If you don't add a page to a menu, people can only access it when they know the link to the page. This way, it becomes a "secret" page, that you can then lock by adding it as a content item to your platform (select content type "External link").