What will humans do if AI replaces our jobs?

I can’t really imagine a future where humans can just do whatever they want because the AI will do all the work. I hear that’s the goal but I have no idea how that can happen in practice. What would governments do to handle mass unemployment? How would it affect the economy as a whole? I don’t know of any examples of what this would look like. It seems so far fetched to me, but I’d love to know more.