This kind of depends upon your knowledge of Python.
If you’re not comfortable with Python, that would be the best place to start. See The Python Tutorial — Python 3.12.1 documentation as one place to get started, along with GitHub - vinta/awesome-python: A curated list of awesome Python frameworks, libraries, software and resources to find other appropriate resources.
If you are already knowledgeable of Python, then your best option is to start with the Official Django Tutorial and then to work through the Django Girls Tutorial. You can check out GitHub - wsvincent/awesome-django: A curated list of awesome things related to Django for more resources once you get to that point.
Where you go after that is going to be up to you. Hopefully you’ve got some ideas for a project that you’re interested in working on - the best way to really learn this is when you’re trying to accomplish something specific.