Is it really important to update your mirror images of kali linux for learning ethical hacking because the course material is pre 2020 so some of the functions and modules like of python don’t run with the newer version but working properly with the old version
It is not important for updating your Kali Linux image. You are just learning and not using it in the production environment. Also, your VM is isolated (mostly) so you don’t need to worry about outdated security patches. If everything runs fine on a particular version then keep it that way, don’t update.
Also, you are provided with the custom made Kali 2020 image made from the original Kali 2020 https://www.stationx.net/custom-kali-linux-2020. This works perfectly with the courses. I would suggest you download this and try to run your programs.