I don't know how to set the PWM resolution and frequency

Official Hardware Nano Family Nano ESP32
1

I want to make PMW 12bit, 12kHz with Arduino Nano ESP32
ArduinoNanoESP32でPMWを12bit,12kHzにしたい

2

Have you looked at the sample sketches in any of the PWM libraries? That is where most people start learning.