Rotating a Part only at a single axis?

I've been trying to make a part rotate only at 1 axis and traditional .Rotate requires 3 Axis, which is not what I need.

Specifically I'm trying to make a camera follow the player, so far what I did is add BodyPosition to the part(CamPart) and attach the camera to it, so that there's a small motion effect.

local function RunRender()
	if CamPart then
	BodyPosition.Position = Character.Head.CFrame:pointToWorldSpace(Vector3.new(0, 10, 30))
	CamPart.Rotation = Character:WaitForChild("HumanoidRootPart").Rotation 
    Camera.CFrame = CamPart.CFrame
    end
end
RunService:BindToRenderStep("Camera", Enum.RenderPriority.Camera.Value, RunRender)

Now everything here works perfectly except that there's too much motion, from every axis and I blame this part

CamPart.Rotation = Character:WaitForChild("HumanoidRootPart").Rotation -- Uses all 3 axis

All I need is for the camera to rotate at a single axis(Left, Right).