2 Questions. Zeds Spawns and Ammo Spawns

I'm REALLY new to this.
I was just messing around and wanting to see if I COULD make a custom map.
I decided to make a "grind map" because its simple and wouldn't require tons of textures and such, and it would be a good base point to start with.

I managed to make a box room, with a smaller box inside of it. The smaller box has some slits in the side where people can shoot / look through, but nobody can climb/run through them. It's meant to just have zeds spawn in a box and be unable to get to players.

The issue I'm having though, is that for some reason, when I build the map, after making the volume and everything, I get errors saying:
ValidatePathingFromMarkers finished but there are no spawn positions! for KFSpawnVolume_0

Even though there are green cylinders in the spawn volume.

And For every green cylinder (there are 12) I get this:
Warning KF-CKPT KFSpawnVolume_0 ValidatePathingFromMarkers: KFSpawnVolume_0 can't find an anchor from marker 0

And there are 12 of those messages, for Marker 0-11.

Any clue what causes this?

As for the second question...
I have searched everywhere for some sort of explanation, but I just don't understand how to add ammo spawns to the map. I feel like an idiot for not seeing it since everyone says it's so simple, but yeah, I still don't see it. xD

2 Questions. Zeds Spawns and Ammo Spawns