OneNote saves automatically every 30 seconds.
It's the end of a meeting but you don't need to save your notes. Why? Because OneNote saves automatically. By default the notes are saved every 30 seconds. They are also saved whenever you close OneNote.
By default all the notes in OneNote are saved in the My Notebook subfolder in the My Documents folder on your computer.
When you open OneNote again, the focus will be where it was when you closed it. So no flicking frantically through a paper pad, trying to find the last notes you took.