message channels supported by Clock PMS+ so you can get notified on new booking creation / uopdate and fetch the respective data;
Bookings endpoint will give you the details of the main guest as well as the other elements you mentioned Booking date, Check-in date, Check out date;
Booking_guests may be used so you can access the details of all guest of the booking if you need them. It is advisable to use this endpoint even if you need only the details for the main guest (first in the list) as the field accept_marketing_emails will help you to meet the GDPR requirements.
After the datasource is created and we set up the integration, we won't be able to see the data right away as we perform import at night time. So you want either wait till the next day or notify tech team and the import will be done today.