What is the command to navigate the previous/next position where my cursor was?
There is no Obsidian command to do that. I can’t remember ever seeing a feature request for that. It would probably make a very good feature request.
There is a community plugin “Navigate Cursor History”. I’ve never tried it.
If you are using Vim key bindings, you can use the ctrl-o jump list, to go back. But I doubt that saves a history between notes.