that newbie thread is for socialising/being silly purposes I think. you'd have to ask the person who started it what they meant by it.
official guides and stuff are here:
depending on what you mean by the newbie, there's also some info on basic forum/IPB functions here:
though it's all default stuff (like iirc it has no info on spoiler tag because it's custom; said spoiler tag can nonetheless be found behind the 'special bbcode' button, to the left of "font" selection).
there are also some pinned threads here and there if any subforum has specific rules, and if you have any issues that are not explained by the above, you could dig through the support subforum to see if it's already been asked about (I suggest either using ctrl+f search if you can think of a keyword that could appear in the thread title, or googling it with "site:bato.to", as IPB's forum search has never been very reliable)