Does the Milky Way Galaxy Have A Surface?

Answer 1

As best as we can tell, everything "has gravity" in the sense that it creates a gravitational field and interacts with other gravitational fields.

This applies even to "massless" particles like photons, which have a relativistic mass even though they have zero rest mass.

Answer 2

Eh.....no. The stars, planets, moons, and space junk that make up galaxies have surfaces but not the galaxy itself.