I opened it up to check it out. For a first map, it seems passable, but there's a few problems that stop it from reaching it's full potential.
For starters, the lights look weird here. Either you don't have enough, or you used a fast compile.
Secondly, nothing is packed. There's missing textures and "ERROR" models everywhere. I suggest you learn how to use VIDE or CompilePal.
Lastly, and I'm sorry I don't have an image for this one, the map seems a bit overscaled and cluttered. It's expected, as it is the first version of your first map, but try working with a 8hu/16hu scale in Hammer, and keep walls to 64hu at the thickest.