"Make me a Combat system for punches that have a Hitbox and a cooldown that will damage Players/NPCs with instructions on where to inser the code"

-- create a part named "Hitbox" inside the player's character model and insert this local script into it 
local hitbox = script.Parent
local player = game.Players.LocalPlayer
local character = player.Character or player.CharacterAdded:Wait()
local humanoid = character:WaitForChild("Humanoid")
local cooldown = false

local function onTouched(otherPart)
    local otherHumanoid = otherPart.Parent:FindFirstChild("Humanoid")
    if otherHumanoid and not cooldown and otherPart.Parent ~= character then
        cooldown = true
        otherHumanoid:TakeDamage(10) -- adjust damage value as needed
        wait(1) -- adjust cooldown time as needed
        cooldown = false
    end
end

hitbox.Touched:Connect(onTouched)

-- insert this local script into StarterPlayerScripts 
local player = game.Players.LocalPlayer
local mouse = player:GetMouse()
local character = player.Character or player.CharacterAdded:Wait()
local hitbox = character:WaitForChild("Hitbox")

local function onMouseDown()
    hitbox.Transparency = 0.5
    hitbox.Size = Vector3.new(5, 5, 5) -- adjust hitbox size as needed
    wait(0.3) -- adjust hitbox active time as needed
    hitbox.Transparency = 1
    hitbox.Size = Vector3.new(0, 0, 0)
end

mouse.Button1Down:Connect(onMouseDown)

-- Instructions 
1. Create a part named "Hitbox" inside the player's character model.
2. Insert the first script into the "Hitbox" part.
3. Insert the second script into the "StarterPlayerScripts" folder.
4. Adjust the damage value, cooldown time, hitbox size, and hitbox active time as needed.