If you are scheduling or holding a meeting and you DON’T have an Agenda, then I suggest you cancel your meeting and prepare an agenda ASAP.
Usually, there are people who are interested in the outcome of a meeting who will contribute to the items that they would like to have ON the agenda so that you can preview your proposed agenda with them and get their feedback / changes.
Once you have an agreed upon agenda, you can then set up a meeting to invite the appropriate people and send then the agenda before hand so that they can prepare for the topics that will be covered.
At the actual meeting, you will then be able to coordinate the discussions to follow the agenda, take any non-planned topics and put them in a Follow Up or Parking Lot list, capture all the decisions, open questions, and action items from the planned agenda items and, finally, publish the minutes with all the useful and on-topic discoveries.
Just remember that effective meetings start with careful planning. So, prepare an agenda and send it out with your invitations.
Good luck with your Meeting Facilitations.