Get List Of All Notes
This action returns a list of file paths of all Markdown files in a vault, sorted alphabetically. It does not return the notes themselves, just their paths.
Use the "Get Note" action with the returned file paths to get the actual note content.
Most of the time you would use this action to get a list of all your notes' file paths, then loop over the results list using the built-in "Repeat With" block. If you want to retrieve the details of the notes, you would use a "Get Note" action and use the loop variable
Repeat Item as the argument for the "File Path or Name" parameter.
If you want to filter the list by folders etc., I recommend using the "Filter List" action from Sindre Sorhus's excellent Actions app (no relation) or a built-in "Repeat With" loop with a contained "If" action.