You do not need to delete a listing to change the images, you will find the images in the sidebar of the listing. Delete them and upload new ones. Click the red cross to delete. See 1.png below.
You need to add some CSS to change the dark filter of the images.
To change the opacity [darkness of the filter], try this CSS – change to suit:
.featured-area::before { opacity: 0.1;}
Read here about customizing CSS: https://wpgeodirectory.com/docs/customizing-your-style/
Make sure to review https://wpgeodirectory.com/docs/supreme-directory-overview/#detail :
The 1st image uploaded is used as the featured image, the suggested minimum size for Featured image is 1400×788. However we must make sure they are not being resized.
To do this, go to GD >> Design >> Home and enable: Resize image large size (Use default wordpress media image large size for featured image upload. If unchecked then default geodirectory image large size ( 800×800 ) will be used.)
Then go to Setting >> Media and set the large size max width to 1400 (or anything you prefer). That will stop you original image from being resized.
Custom fields can currently be added only to the sidebar. However, being this a child theme, it is easy to add custom fields programatically anywhere on the page. We will provide examples soon.