When you set off as a real beginner here, you’re not going to have much knowledge on crypto, and you are better off reading than posting for a while, until you gain some background on the matter, which in turn, helps you to create better posts later down the road.

On the matter of which topic to post on, probably that should not be top of mind right now. As a beginner, and due to what I stated above, it might be better to try to engage in current topics that you may find of interest, rather than opening topics on which you do not much about yet. There are of course questions you may wish to place, and if you can’t find prior topics that answer them, by all means go ahead and ask them.
Once you gather some reading experience, you’ll be able to discern what type of topics you are interested most in, and post about those, be it about Bitcoin, Altcoins or whatnot. Now if the implicit key here is the Merit thingy, the Altcoins are likely to be not the best of options to post about, but, as stated, the driver should really be what you are interested in most.

Old information, as you say, may have it’s value when seen from a historical perspective. There are some valuable historical threads around on multiple topics, and they are an entertaining read. Not sure if this is what you meant (as opposed to stale information, which is old misleading information).

Posting links is necessary when you gather your information from elsewhere. They are nevertheless a reference to a source, not a basis to create a post on their own. You can debate, refute, favour, question, dissect, aggregate ideas, and quote extracts here and there, but the essence of the wording has to be yours. A post including just quotes and/or copy/paste and/or links is generally not going to be that useful, and will lack any personal touch.