This is the result of a project for an applied cryptography class in Winter 2020. I thought it might be generally useful, so I decided to put it up on GitHub.
The article itself is in tour.md, but the individual files are commented thoroughly so if you really only care about one thing you can go straight to it.
If you think it's cool, I encourage you to enroll in a cryptography class somewhere local to you. There's also a freely available draft of a textbook online at http://toc.cryptobook.us. Attending class is certainly a value add over self study, no matter how excellent the textbook is.
Any code here is for learning purposes only and is not to be used in any real situation that needs cryptography.