It sounds like ‘Shared Prototypes’. But, I’d not start in on just advanced behviours until you are comfortable with the basics. You are much better off reading Prototypes and doing some simple task. Ideally test in a small doc and not using your actual data. That way you neither damage you data nor implement methods in the main document until you can do so with confidence.
Although a note anywhere in the document can be a prototype, they is —I believe mainly still there to support very old files where the app was much less capable nd systems were more permissive.
Ideally, make your prototypes in a root-level
/Prototypes container. An easy way to make that (with additional useful customisation) is to add a built-in prototype to your document. It’s not a matter of which prototype, the point is it creates a correctly configured
/Prototypes container for you; you can always delete the added prototype when done.
Although simple examples tend to show prototypes affecting visible things like the colour of a note, that’s mainly sow changes can be seen. However most aspects of a note as an attribute and as such can be altered by changing that attribute. prototypes helps where you want to do a lot of customisation, as you only need to do it once and notes using that prototype inherit all the customisations.
If when trying things, notes using a prototype don’t inherit changes in the prototype it is most likely you have set a ‘local’ value in the note using the prototype. As a local value always trumps an inherited one, you may need to re-set inheritance as described here.
Reading the thread thus far, I think Shared Prototypes are only going to confuse you if you go straight to those.
Let us know how you get on.