looking fo documentation for module files

[Gribouillis]

where does python look for modules before it has site loaded so it can find site.py?

I think it is in <base_exec_prefix>/lib/pythonX.Y where the prefix is the value of sys.base_exec_prefix and X.Y is for example 3.8

Which values do you have for sys.exec_prefix and sys.base_exec_prefix ?