How do you make a cooldown and how do you make something dissapear

help me i need this

Well, for cooldowns, you just use a variable and you lower its value until it reaches 0, and then you would have to check if, when it reaches 0, you can perform some action to reset the cooldown

// The variable that will be used for time
cooldown = 0

update = function()
  // If "cooldown" is greater than 0, it will decrease
  if cooldown > 0 then
    cooldown -= 1
  
  // And if it's equal to 0 or less, then you can place the action you want to perform
  else
    
    // Here's the action
    if mouse.press then
      print("Action! (Cooldown enabled)")
      
      // And you must set the "cooldown" to a value greater than 0 (reset)
      cooldown = 40
    end
    
  end
end

And for something to disappear, it's similar to a cooldown, only it's not for measuring time, but rather for the variable we'll use at the beginning to store the opacity value of whatever we want to make disappear

// This stores the opacity value
alpha = 60

update = function()
  
  // If the opacity is greater than 0, it will decrease
  if alpha > 0 then
    alpha -= 1
  end
  
  // This is just to restart the animation with one click
  if mouse.press then
    alpha = 60
  end
end

draw = function()
  screen.clear()
  
  /*
    Here you use the opacity value; you have to divide
    it by the maximum value it will have (in this case 60)
    
    This is because the system only accepts values between 0 and 1
  */
  screen.setAlpha(alpha/60)
  screen.drawSprite("icon",0,0,20,20)
  
  /*
    And this is just to set the opacity to maximum for
    the other things you want to draw
  */
  screen.setAlpha(1)
end

Schedule----------------------------------------------------------------------------------------------------------------------------------------------------------- 1."after"

after 5 seconds do
  backToMainMenu()
end

2."every"

every 200 milliseconds do
  score += 100
end

3."do"

do     // the code enclosed will be executed in a new separate thread
  for i=1 to 100000000
    doHeavyWork(i)
  end
end

4."sleep"

sleep 1 second

sleep 200 milliseconds

sleep 200 // if unspecified, it is milliseconds by default