To cancel or make changes to your booking, please contact the booking site directly. They are responsible for the booking and payment process, so will be in the best position to help you. As a metasearch, trivago is not directly involved in the booking or payment process. Your booking confirmation will include their contact details and your cancellation policy.
If you didn’t receive a booking confirmation or are having difficulty finding it, you can enter the booking site’s name here for their contact details or for more tips.