What do you want to do? Paint it?
Not really, I just would like to get some water stains out of it and bring back the shine---When I originally bought it, I thought it was immune to spots and didn't protect it as I should have.
Different question entirely. Marble is extremely porous. Bringing back shine might be "iffy" not knowing what you might have used to clean it. Here are some things for you to try.
And then invest in some good coasters so it does not happen again.
Good luck! 🌞