You have a category called "
Welcome to Mirabel"
There are not categories in the sense of.... this page will create your categories, and this for your forums..
A category is made like a forum, but when you set the forum type to be a category it makes is so you can't post in the forum so its acts like a category. Its more a faux-category...
You are using phpbb3.
If they are no appearing even though you created them and they are listed in the admin panel you need to change the permissions, basically you username you are logged in as doesn't have the permissions to view it. (even as an admin)