Octavia vrs 2016 dsg headunit and screen upgrade

Evening all. I have seen a few posts on here of what people have done to there cars and I am looking to upgrade mine. I have the mib2 I think as it has the smaller screen with sat nav and the head ujit has two sd car slots. I am mot very knowledgeable about compatability with my car but the Alpine Skoda Octavia 9" Media System with CarPlay Android Auto i902D-OC3 looks like a good winner. Where is a good place to get this and I'm not sure about what coding is. Sorry to sound stupid just don't have a clue. Hope anyone can help