where? where can i get one?
I have STM32 and Beaglebone too but have not used them yet.
Or google "esp-32" to find store selling a very popular one.
Or check out what's available on sparkfun or adafruit.
Within the past few weeks, they introduced a wireless version - the Pi Pico W. It's about $6 from authorized resellers, though stock is hard to find at the moment.
https://www.raspberrypi.com/documentation/microcontrollers/
https://www.raspberrypi.com/news/raspberry-pi-pico-w-your-6-...