how do i stop this touched event from running too many times?

It seems to me the above answers forgot the wait before resetting the debounce

Debounces are used a lot. They are used a ton for touched events like in your situation. I'm not going to go through the whole process of explaining what a debounce is, but I would recommend looking at the wiki about it.

To fix your code, do what the others have done, but with a wait before resetting the debounce.

local debounce = false

blade.Touched:connect(function(hit)
    if not debounce then
    debounce = true
    local damageCal = math.random(damage,maxDamage)
    if equipped and clicked and character and humanoid and humanoid.Health > 0 and hit and not hit:IsDescendantOf(character) then
        local targetHumanoid = hit.Parent:FindFirstChild'Humanoid'
        if targetHumanoid and targetHumanoid.Health > 0 then
            targetHumanoid:TakeDamage(damageCal)
            print(damageCal)

             end

         end
      end
      wait(3)-- make the cooldown as long as you want.
      debounce = false
end)

The wait acts as a "cooldown", to where the code will not be ran again until the wait has finished.

I hope I helped!

Good Luck!

The answer would be Debounce, what a debounce is basically a pause act.

local debounce = false

blade.Touched:connect(function(hit)
    if not debounce then
    debounce = true
    local damageCal = math.random(damage,maxDamage)
    if equipped and clicked and character and humanoid and humanoid.Health > 0 and hit and not hit:IsDescendantOf(character) then
        local targetHumanoid = hit.Parent:FindFirstChild'Humanoid'
        if targetHumanoid and targetHumanoid.Health > 0 then
            targetHumanoid:TakeDamage(damageCal)
            print(damageCal)

             end

         end
      end
      debounce = false
end)

It detects if debounce is considered false first, then reads the code, but after the if statement, there is a debounce = true this switches the debounce variable to true making the code read once till debounce is set to false at the bottom of the code.