The ESP32 is one of the most powerful and complete microcontrollers commonly used in the DIY and makers world.
It has everything a classic microcontroller has: GPIO, PWM, Timer, ADC, DAC, I2C, SPI, PWM, SD with in addition WiFi and Bluetooth and a low power mode. It is therefore much better to buy a single ESP32 board that contains all these features instead of buying an Arduino board and then a Bluetooth module and a Wifi module that will also be less efficient.
Here are the uPesy boards based on an ESP32:
On most ESP32 boards (with 36 pins), 6 to 8 pins cannot be used like conventional GPIOs.