They usually have a special interest or skill such as photography, clothing or gardening. Other adults help organize a group and run the meetings. Many do both. Sometimes big clubs divide these joins and have several leaders to meet all the interests the 4-H members have. That depends on the size of the club and how old the members are.
Some clubs have junior leaders, who usually assist running the club.
There are many opportunities for volunteers within the 4-H program. Contact the county Extension Educator for ideas. Your main help would be the Extension Educator who are subject matter specialists in agriculture and home economics. Extension Educator will invite you to special training meetings for leaders and give you the materials you need to organize a club. Over 40 projects are currently available in Massachusetts.