Those without an account are probably ahead of the game.
There’s a way to view your profile as if you were a random stranger clicking onto your account. Use that and see all the info someone random can see on your profile. Do you want all that public?
You can limit your profile showing up in search engines. You can limit who can see your friends list, if anybody at all. You know all those pages you liked in 2010? You can turn those off so nobody else can see them. You can limit the audience of the tagged photos of you.
As a professional internet stalker myself, you’d be surprised how much people can find out about somebody based off your FB profile alone.