Hello,
Congratulations about getting your NAAN and getting into the ARK world. There are probably others much more knowledgeable than me, but I think what you need is to 1) mint ARKs and 2) assign ARKs to your articles. You'll probably want to develop a retrospective workflow to address all your existing articles and a prospective workflow for the future. Apologies if I am stating the obvious.
At my organization (UCLA Library) we use both the EZID service and we run our own minter (which is a Java application and very old, I think!) The EZID service is something we have access to as a member of the University of California. However, I see it does cost money for other organizations. See more here:
https://ezid.cdlib.org/learn/.
I hope that's helpful in getting started.
Best regards,
Elizabeth McAulay