Login to Admin > Store Editor > Theme > Profile > You can upload/choose 1 image
Login to Admin > Store Editor > Theme > Background > then you can choose your background type
Login to Admin > Store Editor > Theme > Font > then you can choose your font style
Login to Admin > Store Editor > Theme > Product View Mode > then you can choose which product view you prefer
Login to Admin > Store Editor > Theme > Top Bar > then you can toggle the top bar button