Need help with Junsun Media Centre

Hi there

As the title says "Need help with Junsun Media Centre" running Android 12.0 I have an Android phone.

I have installed this media centre and connected up the following hardware items ;

1) ADAS DVR Front Camera
2) Rear camera
3) GPS
4) DAB system box

1) ADAS DVR Front Camera, How do I get to that section on my unit

2) The rear camera gets its power when the reverse gear/light is operated but does not show on the centre, how do I get to that section on my unit.

3) GPS is working but I can't get to that section on my unit.

4) The DAB system box is connected (as per the instructions supplied) but on automatic scanning, I do not get any radio stations.

The instructions that were supplied are very vague, for example the two USB ports allow you to fit either way up or down.

The English translation leaves a lot to be desired

Audi A3 1.9Tdi 3-door hatchback March 2009 making it an 8P1