This just creates a new note in notes.app. To keep it simple, it just uses the first folder in the first account it finds. You can change this behaviour by editing providing the respective names in the "properties" in the applescript.
To use, just type "n note_text" into Alfred. E.g. "n something very important I will probably forget"
To create a note from the clipboard, type "nclip optional_note_name"