The inlet manifold bolted on the back of the engine shows Efi stamped in big letters on the front, and also mfi will have a distributor cap on the right hand side of the engine, efi has a coil pack instead. Have you got a Haynes mk4 manual ,it’s like a bible for cars and shows you lots of close ups of parts, well worth buying one. We alll had to start somewhere as you are doing now.