I've moved this thread to Script Support. Please be sure to post your threads in the correct forum next time. Thank you.
Basically notetags have absolutely no function on their own. The notebox was originally intended to keep developer's notes about that part of the game.
However, because the notes get saved into the engine, scripters started reading the notes to get more data assigned to the database object.
As a result, you need a script that gives a function to the notebox, and then you need to follow the script's rules on what to write there - and every script has different rules about that, which means there is not one tutorial that can tell you how to use the notetags, you need to follow the script's instructions.
But you can read the tutorial "how to use a script" (linked in my signature), that will at least give you an overview of what is possible and tell you where to look for bugs.