To survive a night easily, you need your car. Once you have it, use it to block half of the road to the courtyard of the garage, then shoot the zombies as they can't go past the car
Why continuing to defend those little crops, with all the birds you have, legendary birds included, you could make millions and buy fruits already made!
Here is a board to show what each upgrade do to your character:
Health: augment the health!
Educability: augment the number of special point your receive!
Accuracy: your bullets goes mores straight!
Speed walking: You walk faster!
Reload speed: Your reload faster! (i tough it only reloads faster after the third upgrade)
Headshot damage: when a bullet goes to a zombie head, it hits harder!
Luck: augment the cash your earn by killing zombies!
I hope that board will help you all!
P.S: all the information was gather when i searched. Like educability and luck that others found and i compiled! (Just to make sure some won't get hungry i stole their data!