From the moon, Earth looks like a relatively small, blue sphere. (Since one side of the moon always faces us, you’d have to be on that near side of the moon to see Earth at all.)
From any part of the moon’s near side, Earth would always be in your sky. It would wax and wane, just as the moon does as seen from our world.
Moon phases seen from Earth – and Earth phases seen from the moon – are always the reverse of each other. When we see a nearly full moon, any moon people would see a slim crescent Earth. And the next time you see a crescent moon from Earth, you can imagine seeing a nearly full Earth hanging in the lunar sky.