Click "Club Management" and then "Teams" from the drop-down menu. From the team overview, click the "Registration" tab at the top of the page.
This page will contain your list of events you are already affiliated with. To add a new event, first click "All Events" at the top of the page. This will then prompt you to search for the event.
Once you have search and found your event, click "Register as Club" to affiliate yourself with this event.