Adding a Header Image
The Header Image, also known as the hero image is a large web banner image, generally placed in the front and center of the Home page.
If you are experiencing issues getting the Header Image to display it is most likely an issue with the overlay color opacity. See this article for instructions on How to change the theme colors.
To set a custom header image, navigate to Appearance > Customize > Header Media. You have the choice of uploading an image or a video, either by uploading a video to your site or by using a YouTube URL (recommended). The recommended dimensions for header images are 1920px x 1080px, an aspect ratio of 16:9 although this is not required.
If you have chosen to use a video, the header image will be used as a fallback while the video loads. It will also be used as the hero image on inner pages, but will be overridden by the page or post's Featured Image if one is set.
Uploading a Featured Image
To upload a Featured Image, navigate to the Edit Page screen of the post or page. Locate the Featured Image field just below the Update button. Click Set featured image and select the background image. Click Update to save changes.