There are a few ways of setting up your programming environment for this course, each with their own pros and cons. This page provides a brief overview.
You can use Google Colab to get free GPU compute (when available). To set up Julia on Colab, you can follow this example notebook.
Note the following two potential pitfalls:
You need to re-load the notebook after running the Julia installation (otherwise the notebook still runs with a python kernel and won't run Julia code)
If you want to switch the Runtime (e.g. to enable one with a GPU), you need to run the Julia install after switching the runtime, because the switch loads a fresh runtime without Julia installed, regardless of whether you've installed it already in your previous runtime.