I can't figure out how to make a page horizontal.
There is no easy way to make a single page landscape, only the whole document. This workaround may help:
- Write your content, then cut it with Ctrl+x
- Select Insert from the menu at the top, then Drawing...
- Paste your content with Ctrl+v
- Click Actions up the top right, then Rotate, then Rotate Anticlockwise by 90°
- Click Save & Close
From here you can size your "drawing" to fit the page. It may help to insert page breaks before and after using Ctrl+Enter to avoid changing the scale of the content.