General comments:

You should be using Python version which is 3.6 or higher.
We will be using the Spyder IDE in class, and this will be the IDE the staff will be most familiar with. So, if you might need help with your IDE, we recommend Spyder.
We have included two instructions for installing Python and Spyder. These were instructions for 6.100A/B, but are equally valid for CSE.C20. We think the easiest option, if you don't already have Python working on your computer, is likely to do a standalone installation of Spyder (versus Anaconda). However Anaconda is fairly straightforward for most people's computer.

Documentation:

Office Python 3 Documentation: a very useful, though sometimes pretty technical, description of Python
Matplotlib Documentation: we will be using matplotlib extensively, and you will likely find it very useful for plotting beyond CSE.C20. This documentation is very thorough and has many great examples demonstrating what matplotlib can do and how to do it.