So, I'm trying to make a sword to 10 damage at a time. Any help?

You need to have a debounce.

local dmg = 10
local debounce = false

script.Parent.Touched:connect(function(hit)
    local char = hit.Parent
    local human = char:FindFirstChild("Humanoid")

    if human then
        if debounce == false then
            debounce = true

            human:TakeDamage(dmg)

            wait(*time in between attacks*)
            debounce = false
        end
    end
end)

Here, use this script that I made some changes to:

local ATTACK_DAMAGE = 10
local ATTACK_DELAY = 1

local rarm = script.Parent:FindFirstChild('Right Arm')
local larm = script.Parent:FindFirstChild('Left Arm')

local debounce = false

function dmg(hit)
    if debounce == false then

    if hit and hit.Parent then --You don't have to do "hit ~= nil" .This works the same too.
    local char = hit.Parent
    if char:FindFirstChild('Humanoid') then
        debounce = true
        local hum = char.Humanoid
        hum:TakeDamage(ATTACK_DAMAGE)
        wait(ATTACK_DELAY)
        debounce = false
    end

    end
end
rarm.Touched:connect(dmg)
larm.Touched:connect(dmg)

Read this wiki for more information: https://wiki.roblox.com/?title=Debounce