Once you get set up with an account on our WordPress system, and log in successfully at this address:
you will see the main WordPress administration interface. Assuming the permissions work the way I think they do, you won’t be able to muck up the installation. But you can edit your entries and create new ones. To do so, use the left navigation sidebar and click on Directory > Directory Listings. That takes you to the area for the Business Directory Plugin that is managing the Catalog. If you’ve used WordPress before, don’t create pages or posts and expect them to show up as listings.
You should see the entries associated with your account. Hover over an entry and you will see an Edit button that you can use to edit the entry. To create a new entry, go to the WordPress menu bar along the top and select New > Listing, select Directory > Add New Listing from the left sidebar. Whether editing or adding, you will be taken to the edit page, described here.