snormanlol:
I thought the ESP32 was something more like a data transmitter, my idea was to do the programming with the Arduino connect it with TXD & RXD pin and then use some serial communication to send the data from the Arduino to the ESP (and then send it to my database)
No, the ESP32 is "intelligent", and far more so than the UNO etc.
Just feeding it with data to send is absurdly clumsy. The "data transmitter" is but one of the many subsystems available to the main processor(s - there are more than one!) in the ESP32.