"Some people say light is waves, and some say it's particles, so I bet light is some in-between thing that's both wave and particle depending on how you look at it. Am I right?" "YES, BUT YOU SHOULDN'T BE!"
Hm, I'd say both the sun and earth orbit the center of the Milky Way.
Or technically the sun is also orbiting Earth, depending on the frame of reference. Or the orbit's center is veeeeeery close to the sun's center (is this what you meant when you mentioned Sagittarius A*?)