Try setting up a Scavenger hunt and have the users find and use the various features. The would document where the found the feature and how to use it providing an example. Try to cover all of the really important features for your use-cases. You could create a template that has the scavenger hunt list using the Checklist feature. Each team member would create a page from the template in their home page or the Team page. Once the complete the hunt they would publish the page an @mention you. If you have different team skill levels you could place them in groups to create a level playing field. Sort of like how golf handicaps work.
