Hey @netlover,
First, you will need to set your page template to a Blank No Container template so that your content will span fullwidth of the monitor. Please see the Situational Page Meta Options here for more details.
You can then either choose if you’re going to set your image as a background image or use an image element. To have an idea of the difference, here’s a comparison.
If you choose the background image method, your image will cover the whole section by default. You will then need to add content to the section making up its height.
If you choose the Image element, you need to ensure that your image’s resolution is larger than your monitor’s resolution. Then, in your Row settings, disable the Inner Container so that your column will span the fullwidth of the section which spans fullwidth of the screen because you’ve set the page template to a Blank No Container template.
Hope that helps.