I don't know about C#/.NET but I assume you are comfortable with general programming concepts. There are several guides that can help you to quickly familiarize with Python syntax. [0] [1]

For Python eco-system related concepts like virtual environment, testing, and other modules, [2] is good.

I don't have any experience with AI/ML, [3] might help if you are looking for books.

[0] https://docs.python.org/3/tutorial/

[1] https://github.com/jakevdp/WhirlwindTourOfPython

[2] https://calmcode.io/

[3] https://pythonbooks.org/topical-books/machine-learning-and-a...