To manage bookings for a particular activity, you can go to the calendar and click on the event you want and then edit or register button:
​

Or you can click on "Bookings" in the top right corner of the page, which will show you all of your bookings, and then select the activity you want by clicking on the activity's name:

Once you are in the event, make sure that you are on the bookings tab where you can see all of your bookings:

From this page you can confirm bookings by clicking on the "Confirm button":

Or cancel them by clicking on the button next to it.

When the event comes along you can print registers or export bookings by clicking on the buttons at the top of the table:
​