If you want to use the Arduino ecosystem that is, ESP32 and ESP8266 don't have anything to do with Arduino. The Arduino core has been ported to ESP8266, but IM

If you want to use the Arduino ecosystem that is, ESP32 and ESP8266 don't have anything to do with Arduino. The Arduino core has been ported to ESP8266, but IMO that's a completely unnecessary level of indirection. Learn how to program the hardware. ESPs documentation is top notch, and C/++, Python and Lua can all be used. Especially the dual-core nature of the ESP32 is not really compatible with the Arduino way of thinking. Just my opinion.