The umbra is right by the moon so this would be a complete dark sphere with no kind of detail or any real textures whatsoever. The penumbra is in a spot where the sun's light overtakes the moon so you would be blinded by light.
To explain about the umbra, it's directly by the moon, so it would just be complete darkness. Since a penumbra is in a spot where the sun's light overlaps the moon, you'll just be seeing light. So in short, for an umbra you'd see nothing but a dark circle. For a penumbra, it'd be the opposite. Nothing but light. I hope this helps!