Relax! There is a lot to check and change in order to make it work, especially if you have installed used parts. My guess is that you have coding for accessories that your car is not equipped with. That's why cruise control is not working and you have those warnings on the dashboard.
First of all what kind of cruise control do you have, normal or ACC? Look in Module 19 (Gateway) -> Adaptations -> Multi Function Steering Wheel Control Module - Version and change it accordingly to you equipment (GRA or CCS for standard cruise control, ACC for, well... ACC)
Next you should check long coding of Module 16. For me worked value
0C 10 for DSG and
0C 20 for manual gearbox.
After each change turn ignition off, remove key and turn ignition on again in order to let modules adapt to itself. If this does not
help then please provide autoscan and we will try other things.