Help Installing a new GPS (Carplay) + new speakers + subwoofer.

Hi everyone, this is my first ever post here.
I just want to let everyone know that I just passed my car exam last Tuesday and I picked up a lovely MEGANE DYN-QUE T-T VVTCVT (2011) with only 77k Miles. Picked it up and drove it home 3 hours, lovely.

Now, I always liked music, and I always liked tech, can someone please let me know what carplay I can buy before I buy anything ? I don't want to buy the wrong thing and honestly I don't know which one to buy. I want one to replace the tom-tom one I have as it is outdated, it works but the streets are wrong and I just want something a bit more modern.

Also, I want to replace my speakers and also add a subwoofer, (the one you can add under your car seat) can someone please let me know what speakers I need ? Dimensions, etc ? Sorry if I ask for too much !