Your Article categories Module displays a list of categories from one or more parent categories.
A note of caution: when setting this up this module you need to pay attention to two similar words:
When you want to try something such as a new module, set the access level to "Special", publish the module on a specific page of your website, and then log-in to the front-end of your website, navigate to the page where you published the module (in this case) and you will see the Module but no-one else will see it.
If/when you are happy, set the access level to, for example Public where everyone will see it.
If you need a little more information you might like to visit Get Help with Article Categories Module.