Trying to make this not inflict self damage but having trouble, advise? [closed]

I'm experimenting with some ROBLOX-Made gear, trying to see how different attributes, like force acting on an arrow, can be modified through simple NumValues. Had some problems in other areas though the I figure would be good to understand if anyone can help

local Tool = script.Parent
local Remote = Tool:WaitForChild("Remote")
local Handle = Tool:WaitForChild("Handle")

local FriendlyFire = false

local AttackDamage = 35
local AttackAble = true
local AttackRestTime = 1

local ProjectileSpeed = 50

local MousePoint = Vector3.new()

local Arrows = {}

--returns the wielding player of this tool
function getPlayer()
    local char = Tool.Parent
    return game:GetService("Players"):GetPlayerFromCharacter(char)
end

--helpfully checks a table for a specific value
function contains(t, v)
    for _, val in pairs(t) do
        if val == v then
            return true
        end
    end
    return false
end

--tags a human for the ROBLOX KO system
function tagHuman(human)
    local tag = Instance.new("ObjectValue")
    tag.Value = getPlayer()
    tag.Name = "creator"
    tag.Parent = human
    game:GetService("Debris"):AddItem(tag)
end

**--used by checkTeams
function sameTeam(otherHuman)
    local player = getPlayer()
    local otherPlayer = game:GetService("Players"):GetPlayerFromCharacter(otherHuman.Parent)
    if player and otherPlayer then
        if player == otherPlayer then
            return true
        end
        if otherPlayer.Neutral then
            return false
        end
        return player.TeamColor == otherPlayer.TeamColor
    end
    return false
end

--use this to determine if you want this human to be harmed or not, returns boolean
function checkTeams(otherHuman)
    return not (sameTeam(otherHuman) and not FriendlyFire)
end**

function getArrow()
    local arrow = Instance.new("Part")
    arrow.FormFactor = "Custom"
    arrow.Size = Vector3.new(0.2, 0.4, 3)
    arrow.TopSurface = "Smooth"
    arrow.BottomSurface = "Smooth"
    arrow.CanCollide = false

    local mesh = Instance.new("SpecialMesh")
    mesh.MeshType = "FileMesh"
    mesh.MeshId = "rbxassetid://223379254"
    mesh.TextureId = "rbxassetid://2740083062"
    mesh.Scale = Vector3.new(0.6, 0.6, 0.6)
    mesh.Parent = arrow

    local lift = Instance.new("BodyForce")
    lift.force = Vector3.new(0, 196.2, 0) * arrow:GetMass() * 0.9
    lift.Parent = arrow

    local hit = Handle.Hit:Clone()
    hit.Parent = arrow
    hit.TimePosition = 0.2

    local projectile = Tool.Projectile:Clone()
    projectile.Disabled = false
    projectile.Parent = arrow

    return arrow
end

function onLeftDown()
    if not AttackAble then return end

    AttackAble = false
    delay(AttackRestTime, function()
        AttackAble = true
    end)

    Remote:FireClient(getPlayer(), "PlayAnimation", "BowFire")

    wait(0.3)

    Handle.Shot.Pitch = math.random(90,110)/100
    Handle.Shot:Play()

    local arrow = getArrow()
    arrow.CFrame = CFrame.new(Handle.Position, MousePoint)
    arrow.Velocity = arrow.CFrame.lookVector * ProjectileSpeed

    local c
    c = arrow.Touched:connect(function(part)
        if part:IsDescendantOf(Tool.Parent) then return end
        if contains(Arrows, part) then return end

        c:disconnect()
        arrow.Projectile:Destroy()

        local w = Instance.new("Weld")
        w.Part0 = part
        w.Part1 = arrow
        w.C0 = part.CFrame:toObjectSpace(arrow.CFrame)
        w.Parent = w.Part0

        arrow.Hit:Play()

**      if part.Parent and part.Parent:FindFirstChild("Humanoid") then
            local human = part.Parent.Humanoid
            if checkTeams(human) then
                tagHuman(human)
                human:TakeDamage(AttackDamage)
            end
        end
    end)    **

    table.insert(Arrows, arrow)
    arrow.Parent = workspace
    game:GetService("Debris"):AddItem(arrow, 10)
end

function onMouseUpdate(targetPoint)
    MousePoint = targetPoint
end

function onRemote(player, func, ...)
    if player ~= getPlayer() then return end

    if func == "LeftDown" then
        onLeftDown(...)
    elseif func == "UpdateMouse" then
        onMouseUpdate(...)
    end
end

Remote.OnServerEvent:connect(onRemote)

I bolded the main areas I'm focusing on. I've tried a few things, none of which are working, and a lot of this is possibly due to my difficulty understanding the first block of bolded code. It seems as though this provides a series of either true or false, but how does the code aggrigate these responses in the next part under checkteams()? It needs to be true to fire the later bolded code, but I'm just a bit confused as to how it got here. Thank you!

edit: Ahh bolding doesn't work here, lemme get the line numbers

ok, 42 - 61, and 128 - 135