Not bad for a beginner. But there is much room for improvement.

In the first screenshot, the second story section of the building that protrudes out needs some support. It would never stay up in real life, and it looks unrealistic when it's constructed like such.

In the second screen, the vast span of space needs to be filled in with something--either additionaly architectural elements or furnitures. Some interior decoration would be nice too. There is also a floating orb of light without a light fixture asssociated with it (at least from what I can see).

In the third screen, the stairs need some railing. Otherwise, players would be falling off it (would just be annoying, not a challenge). And the wall texture could use some improvement. The pattern the texture generated appears repetitive and unrealistic.

These are constructive criticisms, and I am hoping to see the much improved next edition of your map.