Much of the homepage uses the standard Elementor editor.
Hero image
The replacement should be the same dimensions of 2048 wide by 970 pixels. To keep the page load time fast this should be 72dpi and saved as .webp file.
The left side blue overlay will be added when the image is on the website, so need to worry about that, just make sure the content that you want to show is kept to the right side of the image.
Hover over the hero image and click on the blue tab that we will allow you to edit it. If you find this tricky use the navigator.
In the controls for the section click on the “Style” tab. Under “Background” hover over the existing image and “Choose Image” will appear. Upload your new image here and save the page.