I think you’re leaving off the last part - to install torch you need to select the correct config from https://pytorch.org/get-started/locally/ 18 and then run the command it tells you i.e,

pip install torch==1.7.1+cpu -f https://download.pytorch.org/whl/torch_stable.html 28

The last argument is important as it tells pip where the wheels are
I would also recomend using pyenv and pyenv-virtualenv, it’ll allow you to install whatever version of python you want and create isolated environments - see https://github.com/pyenv/pyenv-installer 11