For me, that is, given that you were an admin at the previous place. You are now an admin here.

I know you'll be circumspect. Areas you might routinely use include the "Posts" section of the menu, to work with the posts list and the Topics taxonomy. It's Topics that holds the structure of the site, and where you'd go to add forums ("nodes"), and edit, move, and delete them.

The connection between messages and forums is abstract, by the way. A fancy way of saying that deleting a forum won't delete the messages, only the assignment of messages to that forum. Orphaned messages float around in the "Uncategorized" Category.

The "Proscenium" menu section is entirely my extensions to WordPress. It controls the formatting and behavior of each node (forum). It's kind of a scary place, still.

In general, please don't modify the software: Don't click the link inviting you to upgrade WordPress, don't install plug-ins (they need special vetting in this environment).

Other than that, enjoy! ;-)