FWIW, if you do understand what the flamegraph is supposed to show you, then you might have it easier if you just use macOS's Instruments.app instead. I wrote a blog post about this back in 2015. In short, with Instruments you can get similar insights to those promised by the original flamegraph posts by Brendan Gregg (the creator of flamegraphs).

In 2015 we had Intel processors and now we're on ARM/Apple Silicon, but I think still applies, what with Apple's continued neglecting and kneecapping of DTrace.