DIY Lie Detector Question

https://mad-science.wonderhowto.com/how-to/diy-polygraph-machine-detect-lies-with-tin-foil-wire-and-arduino-0134599/

Step 1: Need Help with Coding

I followed all of the instructions and got to the very end, then I started having trouble with Processing. First of all, I had to delete a couple of lines because Processing wouldn't accept some terms. I did that and a blank, gray box appeared when I was expecting a graph. I know this is somewhat jumbled up, I'm new to Arduino, and need some help from someone who knows what's going on. Thanks.