where to find methods description

I'm working on a project with an ESP32 and I'm struggling with a more generic problem : where to find how to use a method. I.e. I want to get time from a server and I've found example with configTime and printLocalTime and I wanted to check how to call them. I did research with google and in the forum but I could not find anything useful. The same for a more used Serial.print. So the question is : is there a place where method interfaces are described?

Serial.print()

ESP32 arduino core is still in development.

closest to esp32 core is esp8266 core. here are the docs

;D thanks