I could give two shits
It means you’re so uninterested in something, you’d rather die than bother with it. Like you're the king of apathy and everyone else is just a peasant.
I could give two shits about that math problem. I’d rather get a tattoo.
I could give two shits if I don’t pass this class. I’m just gonna play Fortnite all day.
I could give two shits if the world ends. I still have my snacks.