Depends on what your aims are. The Sicilian is far more aggressive, but the caro-kann provides a solidity that the Sicilian doesn’t so much (I’m generalising, it does depend on lines). At the highest level, Sicilian is played when black is playing for a win…
But, and I mean no offence here, at your elo I really wouldn’t worry so much. The flaws in your games at 500elo are much more substantial than what kind of opening you play