We just heard that one of the people booked to do some video recording cannot make it - we would like to record a good number of the events for posterity (and for those people who cannot be there on the day or had to choose between parallel events). At its most basic, you’d put your camera in a static position (ideally on a tripod), point it at the presenter/facilitator and just let it record a whole session. Or you could be more dynamic and be behind the camera for the session, following the presenter and the group discussion to make a more interesting recording ....