If you have a team working on the event together then it makes sense to divide up the roles between you. You may want someone to act as a moderator/host for the event, they greet the attendees, introduce the topic and run through the schedule. You may also want someone to oversee the technical side of the event to make sure everything works smoothly and to also keep an eye on any questions and the chat. You may also have your speakers too who will be in charge of their sections of the event.