"As a minor I signed up for a provocative dating website that now shows my profile - with all its personal details - on the Web when I do a search for my name."
You have quite a problem and do need a CA lawyer, but I think the good news is that because you were a minor when you "signed the contract" you can get out of it. I'm betting that the Terms of Service say that the website "owns" everything you posted, including your picture, and that they can do anything they want with it. Most of them do.
But, as a minor, you can't agree to such a contract in the first place, so it's likely null and void as a matter of law. Have your lawyer threaten them with prosecution under child protection laws for failing to verify your identity. I think there may be a federal law about this as well. I'm betting that the page goes away just about instantly.
