To easily create a copy of a page, just click the "Copy this page" link which appears in the right panel of each page in view mode.  If you don't see this link, then you do not have permission to create a page in the workspace and/or folder the page is currently in.  For security, pages that are created with Copy this page are created in the same folder as the original page and have the same security preferences.

When you click the link, you'll be prompted to create a new name for the page.  You can either keep the "Copy of ..." format, or you can name the new page whatever you need.  Click Copy to copy the page.  You'll be immediately taken to the page in view mode.  The new page will have the same security settings and appear in the same folder as the original.