Creating a new page can be done by copying an existing page or by creating one from scratch.
Above the page tree structure you will find the page+ icon, and by clicking this a menu will expand below, with page type options. (2.1.1)
The standard TYPO3 website generally uses 4 types of page types; 'Standard' (a regular page that you can place content on), 'Shortcut' (to link from the menu within the website), 'Link to external URL' (to link from the menu to an external website) and 'Folder' (a system folder used for special functionality, like news articles). To learn more about the page settings/properties, read about standard page here and for the latter three page types and more, follow this link.
To add a new page, drag the page icon of choice down in the tree structure and drop it where you want it. A page can either be droped between two existing pages, or on an existing page, to make it a subpage. The page title field is automatically opened and here you can insert the page title. Press "Enter" to save. To edit the title, simply double click on the title in the page tree. (2.1.2)