Hi wolfmcbeard, I played your map and I would like to give you my feedbacks.
This is one of my first map reviews, I will try to give you constructive feedbacks since I'm also experimenting with Doom mapping :)
First, the map is not working on prboom+ because it is made in UDMF. This format allows extra features such as the swimmable liquids, 3d floors, auto-scaled textures and light actors used in this map, but is not compatible with prboom+ (Boom format) or vanilla Doom (Doom 2 format).
Overall, it's visible you have put effort on it. There are some complex structures (the nukage room, the elevator, the computer zone), a way to switches and keys and some traps.
I found a bug : the zombiemen outdoor at the start could be stuck because the sector they're standing on is too small.
Things you can improve in my opinion:
Some areas are quite detailled, but others are just bland corridors (the one leading to the switch for the blue key for exemple). Try to have a cohesive level of detail in all the map.
To avoid bland rooms, add texture transitions, height variations, panels in the walls, windows... also use sector lighting, it will add a stronger atmosphere to your rooms.
You used a lot of streched textures, notably for doors and computers, but I find it ugly in some places.
I think there isn't enough monsters. A map is enjoyable when you're forced to fight your way and plan your movement to limit damages and dodge projectiles comming from multiple directions. Traps are a good thing, but are locally limited. Increase monster density, at least for UV difficulty. You can add monsters behind corners or on elevated areas for exemple.
Put more ammo. The only two boxes of shells are availible at the very end. You can make the gameplay focus on ammo starvation but the effect is not the same for this kind of map with a low monster count and big areas because you can barely provoke monster infightning. In fact, I would put ammo where there are traps.
Another point, but it's more a personal though: there is too many doors you can't open and are just here for decoration. Usualy I don't like it because it restricts exploration, notably with the displayed message "That doesn't seem to work". If they arn't meant to be opened at all, I don't think they're necessary, you can put other elements of decoration (see above).
Clearly, the map is designed for GZDoom as it uses advanced features, but I think you should start mapping in a more simple format so you can focus more on layout and gameplay, and learn the basics of texture alignement and sector lighting.
That's an advice from a guy who doesn't map in UDMF though, it's all your choice.
Anyway, it's a good effort for a first map. Keep mapping, you will improve for sure :)