trying to make a script that allows me to change the screen view. i dont know what wont work?

ok so basically i'm trying to change the screen view but it just simply won't work. please help me, all help is appreciated

local cameraHeight = 12
local cameraZOffset = 20
local cameraXChase = 10
local cameraSpeed = .25

local camera = game.Workspace.CurrentCamera
local player = game.Players.LocalPlayer
local RunService = game:GetService('RunService')

local function setupCamera()
    camera.CFrame = CFrame.new(Vector3.new(0,cameraHeight,cameraZOffset),
                                        Vector3.new(0,cameraHeight,0))
end
setupCamera()
player.CharacterAdded:connect(setupCamera)

local function onUpdate()
    if player.Character and player.Character:FindFirstChild('Torso') then
        local playerX = player.Character.Torso.Position.X
        local cameraX = camera.CFrame.p.X

        if cameraX - cameraXChase < playerX then
            camera.CFrame = camera.CFrame + Vector3.new(cameraSpeed, 0, 0)
        end
    end
end

RunService:BindToRenderStep('Camera', Enum.RenderPriority.Camera.Value, onUpdate)

and of course i'm also new to scripting . please try figuring this out