There are a few ways to add an outline to a shape in Cricut. One way is to use the Contour tool. With the Contour tool selected, hover over the outside edge of the shape you want to outline and click. The line you trace will be the outline of your shape.
Another way to add an outline to a shape is to use the Offset Path tool. With the Offset Path tool selected, hover over the outside edge of the shape you want to outline and click. A dialog box will appear where you can specify the distance of the offset. Enter the distance you want and click OK. The line you create will be the outline of your shape.