Reload delay and no reload with full ammo

I need my gun to have a reload delay when ever I reload.
I have a functioning reload but not with delay.
How can I do this?
Also the how do make the gun not be able to reload if my bullet count is full?

private float reloadTimer = 3;

void Update () {
	if(Input.GetMouseButtonDown(0)&& Bullets>0){
				Shoot();				//Start Shooting
			// = true;
			if (Input.GetKeyDown("r")&& AmmoLeft>0){
					reloadTimer = Time.time;
					Bullets = Bullets+8;
					AmmoLeft = AmmoLeft-1;
					AmmoClips.guiText.text = AmmoLeft.ToString();
					Ammo.guiText.text = Bullets.ToString();

You can use a variable to set the next shot time: add to it the shot interval when shooting, and add the reload interval after reloading:

public float shotInterval = 0.1f; // interval between shots
public float reloadTime = 0.5f; // reload time

private float shotTime; // time control

void Update(){
  // only shoot when there are bullets and it's time to shoot
  if (Bullets>0 && Time.time>shotTime && Input.GetMouseButtonDown(0)){
    shotTime = Time.time+shotInterval; // set next shot time
  // only reload when out of bullets and there are ammo clips:
  if (Bullets==0 && AmmoLeft>0 && Input.GetKeyDown("r")){
    Bullets += 8; // load the bullets
    AmmoLeft -= 1; // decrement clip count
    shotTime = Time.time + reloadTime; // set reload time