Hello Emre Yavuzer,
Let me explain you step by step.
Hope my answer helps.
If you have any queries, reach me out.
Create a Separate entity for your images and associate it with your booking entity. Create 1-1 association for your main image and create another 1-* association for your Description images.
Add a File dropper widget in your Booking entity, Configure the widget properly, and the widget has the option to set the Association from the widget itself.
So you will have two file droppers one for the main image and another for description images ( many images).
You generalize your New entity with the system. image or system. file entity based on the upload and View component you are using.