The higher the image resolution - the better the detection will work. In general images with GSD of 2-5 cm/pixel should be sufficient. To detect bigger objects like cars, solar panels, vegetation areas, etc it can be sufficient with 10-15 cm/pixel GSD.
After the Annotation and Training of detector, next step is to start the AI-powered state-of-the art data processing. When you are ready with the detection - export the results for data driven business insights.