The slider on the Home page is displayed via Home page child pages: https://prnt.sc/utad7o. In order to disable the slider and use a static image you may simply unpublish all the child pages but one – this will make a single image displayed instead of the slider: https://prnt.sc/utae20. In order to replace the image and the text you will need to change the Featured Image and the excerpt of the child page itself: https://prnt.sc/utagzh.