What are the Arduino hardware options for experimenting with IoT?
There are many options; which one is &quot;best&quot; for you I leave up to your own research, that could start here:
There's a list of Arduino's based on the SAMD21 that are supported by the FreeRTOS_SAMD21 library here; pick any one with WiFi and BLE.
There are probably a zillion clones out there that could also do what you want, and there is also a FreeRTOS port for the ESP32 (ESP-IDF FreeRTOS, and maybe other ones as well).