Firstly ... Is it Zambies or Zombies?
I pretty much agree with Thompson.
Not badly shot and with some decent editing
Buuuuuut ...
The zombie makeup did need some serious work. The good news is that you know that and you can work on it
Maybe you could practise the makeup a few times before you start shooting so you get it just right ... and ask peoples opinions if it looks good ... basic audience testing!
Zombie attack scenes - This is where you get your scares. your drama, your action ... So it has to be done as well as you can.
For me, the zombie attack scenes were weak. You had some decent suspense for leading up to and in between the attack scenes but the level kind of just stayed there when the zombies attacked ... I feel it needed to be ramped up!
Get fear, anger and most importantly desperation showing in your actress ... Like she is scared for her life.
And try to make the physical action as realistic as possible as well ... those two guys you used as zombie actors could have taken a good hard shove from your actress yes!?
Oh, and please make her use a bigger stick ... one that would bust a head ... ... the stick she used, and the way she used it, was not realistic for me.
So that's me from the armchair

... You are out there making movies! Keep making them!