You can access these files from the course Github repository. The repository will be updated with notes shortly after class. While I encourage you to make use of a local copy of the repository so you can take notes, the version at this site will always be up-to-date and accessible. Execute a git pull in your repository directory to download new files. Prompt files won't change after posting, so feel free to modify them as you like. Here is an informal guide to git.
To develop efficiently, have a local web server running. Python has a simple, built-in server. Use python -m http.server for python 3; use python -m SimpleHTTPServer 8000 for python 2 (execute python in cmd for version number).
How does Javascript differ among popular web browsers? Can I Use breaks down browser support and Browser Usage on Wikipedia shows current market share. Count on your TAs using recent Chrome browsers to evaluate your assignments, but remember that much of the world may not.
Check out the docs for Javascript Object Notation.