Hmm. Doesn't look like very "hands on" to me (README.md). Or then I just couldn't find the document you mentioned in the previous post. But I guess one has to learn these things by trial and error then.
For those looking for tutorials; in addition to the one already linked, I’m quite sure there are quite a few decent YouTube videos about fuzzing with AFL.
https://llvm.org/docs/LibFuzzer.html might also be quite interesting due to the potentially significantly higher fuzzing speed (no fork(2) for each try).