how to use Randoop automatic unit (junit) test

https://randoop.github.io/randoop/manual/

^^Yes, I know many of you will tell me to read the manual. Unfortunately, I don't understand it because I am just a first year student.

What is a environment variable and where do I set it? I've set it so far on my Windows System in Advanced System Settings from reading https://docs.oracle.com/javase/tutorial/essential/environment/paths.html. Is that what the manual means? If not, am I supposed to do something in BlueJ or IntelliJ? Those are the two IDEs I have installed on my computer.

When it says "Run Randoop by invoking its main class randoop.main.Main: java randoop.main.Main command args..." -------- where do I run it from? Am I supposed to create a new class somewhere and copy that into the main method?

So yeah, I'm having trouble just getting started on using it. Having automatically generated unit / junit?? tests would be a good way to bootstrap my learning as I would know how to test the stuff I write.

Thank you for not downvoting.

Edit I see someone has just downvoted. well if that's what gets your rocks off, have a party on my account.