How do I install Concrete Numpy?

You can check the documentation to install Concrete Numpy following this link: Installing — Concrete Numpy Manual

What installation method should I prefer: docker or pip package?

If you don’t know docker well, the pip package installed in a virtual environment (venv — Creation of virtual environments — Python 3.10.1 documentation) is recommended.

If you want an all in one environment with a Concrete Numpy enabled Jupyter Notebook then docker is probably a good choice if you don’t want to set things up yourself. Detailed instructions here: Installing — Concrete Numpy Manual