How much does living in San Francisco really cost?

I’m currently a sophomore in high school, so college is a good two years away, but I want to know these things so I have a good idea of how much things will cost. I’d like to go to the Art Institute
Anyhow, I’m just looking for general information, things from people who’ve lived, or currently live there. How much an apartment would cost, where some of the nicer areas are, how much it costs for you to eat. Just general stuff, because I’m interested.