Cannot get it to turn over?

The VW uses a simple system really. The key triggers a relay which triggers the solenoid on the starter. The first relay can be stopped if the transmission isn't in park or neutral. To test the system, go to the starter and find the heavy wire from the battery. Then locate the smaller trigger wire. Make sure those are clean and tight. Also check the ground cables as well. Try the key, still nothing, go to the starter and use a jumper wire to just touch the small terminal to the main terminal. The starter should turn and engage. If it does you will need to start hunting the wiring for damage that is stopping the power from the key triggering the relay. I would also suggest you go hunt up Mustie1 on YouTube, go to his earlier videos and he does a lot of VW stuff that might help you. There are also a lot of VW forums and groups online that have even more info for members. Attached it the wiring, how to read the diagram and the listing of the parts to get you started.