Hi @AnnemarieB, 
Thanks for your post. For a Group Goal, you can choose between a time, distance, elevation gain, or elevation loss goal, and all activities will count towards the single goal. There is no leaderboard, but you can see how you’re contributing to the group effort. You would not be able to see those who completed the distance in a single activity. 

You could create a club, and create a club event, but you cannot create a goal or challenge for clubs. At this time, Clubs are designed to track members' progress on a weekly basis. Other than the 'Last Week' leaderboard on club pages on Strava.com, we do not store historical data.

Since what you are looking for is not currently available, you could share your idea to our Ideas Board so that others can also vote on your idea. We kindly ask that you review our Idea Guidelines, particularly the “What makes a good idea” section, to ensure that your ideas are clear, concise, and can reach as many others as possible.

Thank you for your contribution, we value your input.