Hi I've got App connect and CarNet on mine, and I have got both working.
Have you got CarNet on yours?
For App-Conect:
I use an iPhone 6S for my App connect - Apple Carplay. Are you sure your Phone and Operating system support App Connect? Have you got a recent update on its Operating System?
You need to connect your phone through its data cable through the USB in the van nearest to the ICE system in the dash.
AppConnect does not work through Bluetooth
Is your cable a high quality or OEM phone data cable?
It should just be plug and play, you shouldn't need to register
For VW CarNet: (You do need to register for this, it's free from VW for the first 3 years)
To get CarNet working you need to register your VIN Number on the VW Carnet site, I have a VW CarNet App on my phone( from your app store), which I have registered.
Mine would not connect through my phone, I am not sure if it was an IPhone thing or a Vodafone thing.
To get it working I purchased a VW CarStick from Amazon (not cheap around £85), and also a "3" data only sim card £30 for 16gb/1 year of data.
I can also set up the van as a Hotspot and connect other devices through it, it works really well, as a hotspot, but the CarNet is of very limited use for me.
Not sure if any of this helps, but there you go anyway