Legal Question in Business Law in California

I suggest that as a starting point you invest in a Nolo Press soft-cover self-help law book, "How to Form a Nonprofit Corporation in California." I believe the author is Anthony Mancuso, and I believe there is a relatively current (2011 ?) edition available.

Please note that there are two important and quite different steps in "forming" a nonprofit corporation (or other nonprofit entity). The first is to form the entity itself, which is almost always done by filing papers with the California Secretary of State. The second step is to obtain IRS recognition as a nonprofit organization, and this is by far the more difficult step, but is necessary if you intend to solicit and accept charitable contributions that the donors can deduct on their taxes.

As to the age problem: I do not know of anything that specifically prevents a minor from forming and operating a nonprofit. I hasten to add that there are some legal problems that may make aspects of it difficult, including lack of capacity to make an enforceable contract. There are some possible solutions: (1) Wait until you are 18; (2) Find a responsible adult to act (without pay) as your general manager; or (3) become "emancipated" by asking a court for a "declaration of emancipation." Obtain a copy of the California Family Code at your county law library or on line, and look at sections 7000 through 7143, especially 7120-7123.