The page you need to edit is MediaWiki:Wiki-navigation - insert whatever links you want there. To the rules page you already created, to your user page (as the admin) - User:Ismailrblxyt, etc. I still don't get what is a report center.
Well, you can technically create such a page and let people report stuff in the comments, but this is a very uncommon approach.
Violations shouldn't happen that often, and people can contact an admin or mod on their message wall. For posts, there is even a built-in "Report" feature. I'm afraid creating such a report center would encourage drama, bad-faith reports, or even encourage violations because they bring so much attention.