Is there a lounge or lobby the parents can seat while waiting for the kids to get out of a concert??

There is a lobby but not a lounge.

There's a lounge upstairs and a lobby area downstairs. The lobby has very limited seating.

Cannery: I only remember the bar area for sitting but they may configure differently. Check out website photos also.

Mercy Lounge is upstairs. The ballroom itself has tables and a bar.

There is an outdoor deck area if the weather is nice.