How can I make my ad categories appear live on my site?

I’m trying to use WP Classified and I’ve been creating the categories of ad that I need. However, maybe I’m being really stupid but I cannot work out how to go from having created the categories to having them actually appear on the live site. I can’t see any way of assigning them to a page, or creating them as a page, or publishing them or activating them. I’m sure it’s a simple step but I cannot find out what.