Leaders plan and deliver the programme and run the evenings and events. There are more than one Leader per section (Beavers or Cubs or Scouts) so it is a collective role where you can do as much as you feel comfortable with whilst learning from those more experienced. Section meetings are between one and a half hours and two hours and since there are multiple Leaders it does not have to be an every week commitment. We have a planning meeting once a term and section evening preparation can be split between all Leaders, Assistants and Helpers. Many hands make light work.
Generally we organise it so one leader will take the front role for an evening section meeting and perform the opening and closing ceremonies and be in charge” for that session. Someone else might do the same the next week.