What do you usually do first when starting work on an existing project?

The first thing I usually do when starting work on an existing Python project:

1. Read the README and documentation to understand the purpose of the project and its main features.
2. Set up the environment: install dependencies from the requirements.txt file or Pipfile.
3. Run the project locally to ensure it works and to understand its behavior.
4. Study the code structure, main modules, and entry points.
5. Check the version control system (e.g., git) to understand the change history and the current branch.

This approach helps to quickly immerse oneself in the project and start working effectively.