Adding pages to a Confluence space is simple. If you have permission to add a page to a space, you will see an "add" button in the upper right, and in its resulting menu, the option to click "Page." Confluence then opens the editor, and you can begin adding content. Each page must have a title; Confluence won't let you create a page without one.
In a Confluence space, all pages are either parent pages, child pages, or both. While viewing a page, if you start another, it automatically becomes the child of that page. The first page you create in a space will automatically be a child of the home page, because the home page is created automatically with the space itself. Pages can be children of other pages that are, in turn, children of other pages.
You can edit this hierarchy of pages, moving pages around and changing which pages are parents or children of others, by clicking the three horizontal dots in the upper right, and from its menu, choosing "View in Hierarchy." In the following screen, you can move pages around within the hierarchy by clicking and dragging them.
Here's a video demonstrating how to create pages, and rearrange them in the parent-child hierarchy:
Confluence pages are just as easy to delete, too: Click here to see how.