How do I make this Punching script debounce?

What you want to do is create a bool variable right before the function, then when it fire, check if the bool is true if so make it false, at the end of the function wait a few seconds then make the bool true

ply = game.Players.LocalPlayer
repeat wait() until ply.Character
char = ply.Character
mouse = ply:GetMouse()
local debounce = false
local CanDamage = false

anim = {

equip= "rbxassetid://1007180526",
leftpunch = "rbxassetid://1007372513",

}

equip = Instance.new("Animation", char.Humanoid)
equip.Name = "Equip"
equip.AnimationId = anim.equip
lpunch = Instance.new("Animation", char.Humanoid)
lpunch.Name = "LeftPunch"
lpunch.AnimationId = anim.leftpunch
combat = false

function combats()
    local ran = math.random(1)
    if ran == 1 then
        char.Humanoid:LoadAnimation(lpunch):Play()
    end
end


function key(key)
    key = key:lower()
    if key == "2" and combat == false then
        print("hi")
        equips = char.Humanoid:LoadAnimation(equip)
        equips:Play()
        combat = true
    elseif key == "2" and combat == true then
        equips:Stop()
        combat = false
    end
end

enabled = true

local d = true --debounce
function punch(key)
    if d==true then d=false --check debounce
        if combat == true and enabled == true then
        combats()
        enabled = true
        end
        wait(2) --debounce wait
        d=true --reset debounce
    end
end

mouse.keyDown:connect(key)
mouse.Button1Down:connect(punch)

Also you should learn UserInputService