Booking is done online and is confirmed instantly. Just go to the activity you're interested in, choose the date, time and number of people to see the price before completing payment. If an option shows no availability, it means there are no spots left for that time.
Before completing your purchase, you can review the main details of the activity, such as what the booking includes, the applicable conditions and, for a guided tour, how the experience works. Once the process is complete, you'll receive confirmation with your booking voucher and everything you need for the day of your visit.
If you book an activity with a guide, that confirmation will also include the meeting point and basic instructions for joining the group. That way you can lock in your visit in advance and arrive with all the information from the start.