Individual - Select if you are tracking your own mileage only.
Family/Group - Select if you are doing the challenge with children/youth or if you want only one person to manage all aspects of the challenge for the entire group. For example, a scout leader or a parent on behalf of their family.
Organization - Designate a leader to start the group and receive a join code. Each individual then registers themselves using the organization's code. If you have a join code, go directly to Join a Challenge tab.