To install CLI apps, you are encouraged to use pipx.
To develop, you need Poetry.
Poetry will install all other dependencies for you to start hacking right away:
# Install tools
pip install pipx
pipx install poetry
pipx ensurepath
# Clone
git clone https://github.com/OCA/oca-addons-repo-template
cd oca-addons-repo-template
# Install development environment
poetry install
From now on, whenever you want to enter this development environment shell, just:
poetry shell
Specifically, to run tests:
poetry run pytest
Please follow the official guide from the OCA Guidelines page where applicable (most of it relates to Odoo-specific code, while this one is a template and some things just don't apply here).
Here you will find a good guide so you know how to contribute to this and many other projects: https://opensource.guide/how-to-contribute/