My question involves name change laws in the State of: California/Florida.

When I was 10 months old, my birth father passed away. When I was 8 years old, my Mother remarried and decided to change my name without going to court. Since then, all of my school records, military record AND social security information are under the new name. With a name change becoming necessary for licensing and passport requirements, I can't find information to assist me. I was born in California, but currently live in Florida. Which state do I need to petition and where can I find these requirements? Thank you.