In the schedule, you can create your own events. When you choose an activity, there are a few dozen activities already suggested in the list. You can pick one of those, but if the one you're searching for is not in that list, you can create your own schedule activity. Just scroll down the list and click "add new activity..." Fill in all the information required and don't forget to tick the box that says "Can be added in schedule".
After you've added the activity, you will be redirected to the activity calendar. Just go back to your apps, choose schedule and create a new event again. You will now see your custom made activity is now at the top of the list, ready for you to use. If you've added a Youtube link to the activity, you will be able to play this once adding the event to the schedule.
If you want to go back to the activity and adjust something, go to your business settings and click on your activity under schedule settings. This will bring you back to the creation page and you can change whatever you want.