I'm not an Emacs user per se, but I am an org-mode user. I don't even know where to begin to start recommending org-mode, it is a literal life changer. It is everything that you've ever wanted in any note-taking app (Except perhaps syncing with mobile devices, but people are working on that).

Seriously, go through the fine tutorial and just start exploring it. No matter what you put off for doing that, it will be worth it.

https://orgmode.org/worg/org-tutorials/orgtutorial_dto.html