It may take a few tries at midnight to log in. Also, if you find something you want is booked up. Try again daily for the next week or so. Some people book things right away to reserve them, and then change to something else in a few days. We were travelling as 9 people and that first night we got everything we wanted except one excursion that we could only get 5 places for, not 9. So we booked those five. Within a week (trying every day) we were able to get 4 more. So it worked out for us. Keep trying and don't panic!