The galaxies orbit each other mutually as mass clusters in a point of balance as they travel thru space. Milky Way and Andromeda are in a spin with each other as they are closest to each other. But they're all spinning around each other instead of a larger central mass.
That’s a question with a bit of a longer answer. More-or-less, nothing. The Milky Way and the Andromeda Galaxy (along with the Local Group) “orbit” a shared centre of mass (they all orbit one another). We will eventually collide with the Andromeda Galaxy. Beyond this, as part of two superclusters (Virgo and Laniakea) we are all drifting toward the Great Attractor which itself is drifting toward the Shapely Supercluster. Unlike our circumstances with respect to Andromeda, due to universal expansion (dark matter keeps us accelerating at a rate which overcomes gravity), we shouldn’t ever reach the Shapely Supercluster. So while we’re being pulled toward it, we’re actually moving away from it.
Andromeda in the first instance, though they are more pulling toward each other than orbiting. Then the Local Group, a fifty-galaxy neighbourhood, then the Virgo cluster, then the Laniakea supercluster.
After that probably some larger cluster, I'm not sure where it ends
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u/sjayvee 12h ago
I feel so stupid.. the sun has an orbit?!