A simple, fun teams event, the Mixed Pivot teams requires that there is at least one woman and one man in your 4-player team (you can have a 3/1 ratio if you wish). You will then play a set number of boards with each member of your team ... for example if the event is to be 27 boards, you will play 9 x 3 board rounds, so 3 rounds with each of the other three team members.
It is an excellent opportunity to join up with another pair of friends for a fun evening of bridge, hoping that you don't have too many misunderstandings over the course of the evening.