In your site administrative options, there is a “Create Content” link. If you expand it, there is a “Page” option there.
When creating a new page, you should:
- Give the page a Title
- Add a Menu Link Title (and assign the page to appear in your Primary menu)
- Paste or type some text into the Body area (if you paste, use the “Ctrl + Shift + v” method). Feel free to add images using the little green tree (insert/edit image) icon.
- When you are ready, click the Save button at the bottom of the page. (Images should not be larger than 400px wide, but there is a resize tool available when you browse the server to locate your image.)