Each section has a varying number of rows and seats per row. If you already have tickets, find your seats for row and seat numbers.
As you face the stage from your seats, lower number seats are on your right.
All general admission seating on the Floor for the Twenty One Pilots concert is in the same section. Some tickets may be marked with a row or seat, but these details are irrelevant. Arrive early for a chance to be as close to the stage as possible.