If you just Google the name of the MCU followed by pinout you will find all the details you require. They are effectively the datasheets without which you can’t use the MCU’s.
Arduino, Espressif and others all have very detailed schematic’s etc for their MCU’s.
The details for the special pins of the ESP is harder to locate as the information is scattered further afield on the internet. The datasheets for the various ESP’s mention the pins that have to be high or low during flashing / running and it’s the same for all ESP’s.