The Team Leaderboard tab shows the teams in the event (e.g. Team XYZ in the NYC Marathon) and the Top Individuals tab shows individual participants, regardless of what team they're on.
Some events may have one or both of these tabs disabled. There are also various controls for how these are organized. For example, it may include or exclude Offline Donations from being taken into account in the leaderboard standings.
Contact your campaign organizer to find out how your event leaderboard is set up, then try to make it to the top.