I apologize for posting repeatedly. I think I succeeded in installing numpy and other libraries as well.
In case for someone in same situation, I would like to share my own case resolution.
After installing pip, not from c4dpy, but using the python below worked:
/Applications/Maxon Cinema 4D 2024/resource/modules/python/libs/python311.macos.framework/python
and executed the command like python -m pip install numpy normally.
And worked inside C4D properly.
If there are any inaccuracies or clear errors, I would appreciate it if you could point them out. Thank you in advance.