Camera focus and cframe won't work? [CLOSED]

For some reason, I can't get my camera to work. I've been trying to focus and CFrame but it won't move. ;-;

If you can't use a while true do loop.. then e.e

		if a ~= nil then
			while true do
				--cam.CameraSubject = a -- a = a part
				local Pos = a.Position  -- a = a part
				cam.CameraType = "Scriptable" --maybe breaks it?
				cam.CoordinateFrame = CFrame.new(Pos) --e.e
				cam.Focus=CFrame.new(300,300,0) --e.e
				wait()
			end
		end

So the camera attaches to the part, then it needs to face a certain way, but it doesn't and no matter what value it is, it stays the same. Any help?

ty

if any questions/concerns just comment I'll answer. I'll try to do a better explanation if you need it.