Anaconda, a stable and coherent distribution of Python for data science. It is strongly recommended that you uninstall any version of Python 3 you may have on your computer and install the latest version of Anaconda. This distribution includes Python, a Python editor (Spyder), several basic libraries for data science (numpy, scipy, and more), visualization libraries (including matplotlib), machine learning libraries, including scikit-learn. This distribution places all relevant files in the appropriate places, and you won't have to struggle with linking libraries, etc. Once you installed Anaconda, run the Anaconda Navigator and familiarize yourself with the tools. Pay attention in particular to the Jupiter notebook launcher, as you will submit homework as Jupiter notebooks.
The official Python 3 Documentation also includes a tutorial. Use the library reference and the language reference as your official sources of information about Python 3. You can also find information by googling, but make sure you refer to version 3 of Python if you do so.
Several tutorials on Jupyter notebooks can be found online. Here is one from Dataquest.