Your venue account gives you a view of what's booked, who's coming, and what you've been invoiced, without ringing the agency to ask.
Set up your venue details first: address, the areas or rooms you book acts into, and a contact. If you have more than one space, add each one, because acts need to know which room they're playing.
Add a photo or two. Acts look, and a venue that's shown itself gets better engagement.
If your agency already had you on GigSpace, your account links to the existing record and your history comes with it.