someone please teach me something...

Cool.... How do we begin?

@Tracos you begin by looking at the things around you, observing them. Look what light does to materials, observe how the shadow blends in with the object at some points and how light blends in them at some other points.
Look at the outline of various objects and observe how some are bold and obvious and other fuzzy and not clear, depending on the light.

That already sounds kind of advanced.... Or are we just looking at the moment?

just look around at the room you're in, better a physical object!