Should I run away from home and then come back?
No, it's not. Deal with your boring life.It's better than getting robbed, sexually abused or even killed on your adventure. Your parents will report you missing and your actions will cause taxpayers a huge amount of money lookIng for you on your adventure. Think of how worried your parents will be. Why don't you go to soccer camp instead?
I'd suggest somewhere closer, like Nashville.
Despite the image, San Francisco is NOT a friendly place to come to for young people on the street. Now, you have money, yeah, you might be ok. But if you are planning on moving there and panhandling, you may discover, as so many young kids do, that there are some pretty nasty people in SF who prey on younger kids. Rape, mugging, forced prostitution or just hunger and tiredness and quite possible likely outcomes if you are broke and plan on living on the street.
Drop me a line if you decide to go, so I can try and talk your out of it again.