Writing
Blocks and the slash menu
A note is made of blocks. A / at the start of a line opens the menu you pick the block type from.

The block types
Paragraph, heading in three levels, bullet list, numbered list, checklist, quote, code, divider, image and table. Enter starts a new block; backspace at the start of a line merges it into the one above.
The slash menu
Type / at the start of a line. The menu opens at the cursor, even if the line already has text: the text stays, only the block type changes. Keep typing to filter. The search is forgiving, so "ueb", "üb" and "ub" all find the headings.
Shortcuts, once you know them
At the start of a paragraph these turn the line straight away:
| - | bullet list |
| 1. | numbered list |
| [] | checklist |
| > | quote |
| ``` | code block |
| --- | divider, on the line break |