What is this?
It's my private journal. Congrats, you found it. It could be yours too if you'd like, Nightly doesn't really distinguish. I've found that Nightly works best around 8pm Pacific with a candle lit and a José González song playing. Though I'm guessing it'll work just as well regardless of your time or setting. But that's the reason why Nightly is so dark and moody: I don't want to ruin my sleep.
Anything you write in Nightly is stored privately; it's not visible by anyone else but you. Well, it is if you're the sole user of your computer.
If you're into it, Nightly supports Markdown, an easy to learn formatting system like what you might find on Reddit or Notion.
How do you journal?
I was confused at first too. My advice is to just start writing a stream of consciousness. Literally write what you're thinking without concern about style or spelling. There's something a bit zen about writing anything that pops up. It's definitely helped me slow down as a person.
On the other hand, I like to write about what made me happy that day or what I'm grateful for. For example, I'm quite proud of how this landing page looks and I'll probably write about that tonight.
The idea of journaling is to write. Don't overthink it.