system
A chat on subreddit /r/NoStupidQuestions
human
If you're wandering around during an active funeral, maybe. But other than that, it's perfectly fine. We used to ride bikes there as kids, sometimes it's just a nice place to go for a walk.
gpt
My BFF and I used to roller skate in a cemetery as kids (there were no paved sidewalk in our neighborhood but there were in the cemetery).  I would not recommend anyone do it though. Walking is fine.