this is very impressive for a first map, good job! I'll run around a bit later and drop a bit of feedback for you
edit:
unpacked texture
reform your spawns so players don't immediately have to do a 180° turn
the area off to the right side of the spawn is kind of out of the way and nondescript, not to mention a lot longer route to mid. I'd try to change the geometry outside of spawn to make that route more intuitive/ useful.
this staircase is very thin and would be hell to push up with an enemy at the top. I recommend making this more like house in viaduct
this is a very narrow angle, and would be awkward to use and/ or even notice. For now just push the stairwell further into the room so the top landing is squarer. You might have to put a 90° bend to get it to fit
would be nice to be able to easily walk off these balconies, also, clip the vertical fenceposts as you get stuck on them very easily at the moment
your displacements all have hidden faces enabled, only turn the visible faces into disps
as a whole i like mid, but your point building/ cap zone is pretty small so anyone standing on the point will catch a
lot of damage. probably annoying to hold because of this
more missing textures, remove this barrier
this flank is dull and undeveloped at the moment, try to come up with something to make it more interesting. If you want to pander to the koth clichés, chuck a healthkit somewhere over on this side
i like the dual layered mid