Help With Aftermarket Radio/ Stereo.

Hello, I'm new to this forum so wasn't sure where to post this, decided general discussion was the best place to post this.
Anyways, I've recently passed my driving test and my Dad has offered to hand me down his Chevrolet Cruze LTZ 2012 Hatchback (He's getting a Ford in December).
I've been thinking about getting a subwoofer installed in the car but my friends tell me I might run into issues with the stock radio. I'm completely inexperienced
when it comes to car installations and after doing some research online I can't seem to find anything useful. So I came across this forum and thought this might be the best
place to ask.

So long story short, I want to install a subwoofer (doesn't matter if it's active or passive) and I need to have some recommendations on what to change out and what to buy also.
I can't post any links since I'm new but the best way I can describe the radio unit is that It has a full colour screen with navigation etc. Plenty of buttons under it. That might not be relevant
but I'd like to provide as much info as possible.

Any installation advice would also be greatly appreciated!
Lastly, I'm UK based if that means anything.

Thank You!