Legal Question in Family Law in California

You have a problem with paternity that should probably be addressed first. I suggest speaking in person to a family law attorney. The reason that I mention this is that while you may not know who the "biological" father is, there may be a "legal" father who has the right to notice over a legal name change. That sort of thing has to be ironed out with an in depth consultation with a competent attorney who is familiar with California's paternity law, to determine who the appropriate parties are, if any. Otherwise, any petition for a name change of a minor is just going to get denied or rejected by the court system.