You can change genesis setting from the Dashboard sidebar menu, hover over “Genesis” link on your left menu and click “Theme Settings“. These are some stuff that you can do from the Theme Settings menu :
You can change default layout from Genesis Layout
Change your content so it only shows the excerpts. Default is Show all Content / Entry Content (all content will appear). Choose Display : “Entry Excerpts” to have automatic read more button in each post and make sure “Include the Featured Image?” is checked. Image size : autoreadmore, image alignment : center.
Default is Show all Content / Entry Content (it means you have to add read more button manually), here’s the setting :