FreeCAD’s Python functions are all well organized in different modules. Some of them are already loaded (imported) when you start FreeCAD. Just try:
dir()
https://wiki.freecad.org/Python_scripting_tutorial
https://wiki.freecad.org/FreeCAD_Scripting_Basics
https://wiki.freecad.org/Python_console
https://wiki.freecad.org/Power_users_hub
https://wiki.freecad.org/Debugging#Python_Debugging
https://wiki.freecad.org/Profiling
…
https://musicbrainz.org