You have to select an object before you can change it, whether that would be to move it, apply a color to it, modify its shape, or whatever. You have several ways to select an object, including the following:
Use the selection tools in the Toolbox to select the whole object.
Use the selection tools to select individual nodes on a path or shape.
Use menu items to select all objects or only objects with particular attributes.
Use the Layers panel.
Microsoft Expression Design highlights an object when you select it. You can see a path's centerline, an underscore beneath text, nodes on shapes, and so on. These highlights are drawn in a color specific to the object's layer. Selected objects are typically also surrounded by eight handles that you can use for scaling, rotating, and skewing the selection. (If you prefer not to see these highlights, see Turn off selection highlights.)
Note that some objects cannot be selected at all, including locked objects, objects on locked or hidden layers, or object guides.