At the moment I have about a million notebooks, all for slightly different things.
Obsidian seems to be the most common choice here.
Off the top of my head, I have the following notebooks:
Dipped my toe into this before, using Anki. I know it works, but it’s a matter of making it a habit. I also have this problem where I overload my deck with too many vocab cards at once and gum the whole thing up.