I have a problem with mkvirtualenv. When I try mkvirtualenv py39 --python=/usr/bin/python3.9 I get File "/usr/lib/python3/dist-packages/virtualenv.py", line 25, in import distutils.sysconfig ModuleNotFoundError: No module named 'distutils.sysconfig' . Thanks
The one concern I have is that you appear to be running a version of python newer than what is shipped which could be causing the issues, but for a stock install the following steps should get it working for you.
Make sure you have installed the virtual tools
sudo apt install virtualenv virtualenvwrapper
Source the wrapper script
mkvirtualenv should work now.