If their comfort level is limited due to lack of experience, I tend to sandbox them somehow and then walk them through a couple examples of “danger” vs “ok, this definitely won’t be irreversibel if it’s wrong, but I think it will do what I want.”

A couple of my go tos are the obvious rm -rf / vs ./ and a sed with and without -i on some random text file.

That naturally segues to “here’s the man page, here’s how to use it and search it.”

That tends to give them some confidence that they won’t accidentally cause real damage, and make it seem like they aren’t just typing arcane magic spells, but actually understanding how to responsibly put the pieces together.