How to do Ammo UI in Unity 5.3.4?,How to do Ammo UI in Unity 5

So I was wondering in Unity 5.3.4 how I can make a UI that will say this on screen “Ammo: 30/150” then when you shoot the “30” goes down until it hits “0” and when it hits “0” you can’t do anything unless you hit “R” (For Reload). Then when you press “R” (For Reload) it will reset back to “30”. I’ve looked all over YouTube and cannot find one tutorial and if I did all I find is GUI which does not work with Unity only UI does. Trust me I tried it a billion times. Please help, Thank you!,

Well, GUI would work like this:

int currentAmmo = 28;
int maxAmmo = 30;

void Update()
{
        // Reload with R
        if(Input.GetKeyDown("r"))
        {
                if(currentAmmo != maxAmmo)
                currentAmmo = maxAmmo;
        }

       // If no Bullets, can´t shoot
        if(currentAmmo != 0)
       {
                   if(Input.GetMouseButtonDown(0))
                                 currentAmmo--;
        }
}

// This is your ammo counter
void OnGUI()
{
      GUI.Label(new Rect(10, 10, 150, 50), "Ammo: "+currentAmmo+" /  "+maxAmmo);
} 

Haven´t tested this but it should work.

With the new UI System you should use getComponent to assign a Text Variable and change the Text from the UI Text with:
Text VariableName;
VariableName.text = “AmmoCounter”;

This Tutorial should help:
https://unity3d.com/learn/tutorials/modules/beginner/ui/ui-text

Good Luck!