How do i make the camera Sway? Upon Idle

You can try using this code.

local RunService = game:GetService("RunService")
local camera = workspace.CurrentCamera

local speed = 3
local intensity = 0.5
local focusIntensity = 1.1
local smoothness = 0.2

RunService.RenderStepped:Connect(function()
	local t = tick()
	local x = math.cos(t * speed) * intensity
	local y = math.sin(t * speed) * intensity

	local cf = CFrame.new(Vector3.new(x, y, 0), Vector3.new(x*focusIntensity, y*focusIntensity, -5)) + camera.CFrame.Position

	camera.CFrame = camera.CFrame:Lerp(cf * camera.CFrame.Rotation, smoothness)
end)

Video: