Guidance with ESP32 audio processing from bluetooth

Hi all, I'm just getting started with the ESP32, and I was hoping for some guidance/buzz words that I can research.

I'm hoping to connect from my phone to the ESP32 via bluetooth, then perform an FFT using an arduino library on that audio data which will eventually be displayed as a spectrum analyzer on an LED matrix.

Also, how can I use an external bluetooth speaker to play this audio? Or do I have to implement speaker drivers in my project