As a new forums user (not just WoW), whenever I post I feel a twinge of anxiety, thinking what I said was stupid or the wrong type of thing to post.
The “official” code of conduct can be found below. But be aware that there are things in there that aren’t specifically mentioned that are still violations due to the way it’s loosely worded. For instance, self promotion by linking your own youtube content, or mentioning things like Blue, Blizzard, or a specific Blizzard employee by name in a thread title.
You sort of pick up on the unwritten rules just from being around long enough, and rest assured if you post something that is a known violation, people will generally let you know in the thread.