To add a page to your report, go to the bottom of the Pages panel on the right-hand side of your Designer client:
Alternatively, duplicate one of the existing pages:
Duplicating a page is a quick to get a new page with all standard objects already in place – such as page header, page footer etc.
Duplicated objects (on duplicated pages) will by default be linked with their original objects – ensuring easy central management of the objects.
In fact, from the Object list, you may consider to “unlink” an object on the duplicated page. This is necessary if you plan to make changes to an object that should be specific for the object on the current page only.