So yeah, it's my first try at mapping... so I hope some of you guys wouldn't mind helping out once in a while

I found quite some tutorials, but some websites seem to be down, so that's why I might need some help with making the map. But I've got 3 rooms so far, the start room, a second room, and an upstairs.
The starting room has 3 barricades, the 2nd room has 1 barricade, and the upstairs room has 0.
The spawners are not set up properly so the upstairs room might get a spawner and a barricade.
Here are some images:
Starting room


2nd room


Upstairs


And a balcony...

I still need to set up a skybox and what not, but I'm planning on making the map take place outside the building as well.
Besides all that, I tried to put in a zombie counter, as you can see... But it doesn't really show how many zombies are left...
It just says 0 all the time, any help would be aprieciated! Be free to make suggestions for changes as well ^^;
Oh and the power switch location is temporary, it will be placed somewhere else later.
But yeah, that's as far as I got, I hope I'm doing okay for making a first map ^^;