A scene, when created, has a single default light source, set as a distant light, and the "handle", or physical object that represents the light, is situated central to the scene, a little above the grid plane. The default direction is straight down, but you can change this by selecting the light object and, in Top view, rotating the light object in any direction you wish. For a distant light, the actual position of the light object within the scene makes no difference, because it defines parallel light rays. If you are having trouble finding it, make sure wireframe mode is selected and find the object light01 in the key frame editor at bottom left of the screen. If it is not there (and hasn't been renamed) it might have been deleted, in which case just Build>Add Light and place/orient a new one.