A couple of questions about the legality of a 16 year old running away from home?

I'm 16 and thinking about running away, but I have a couple of questions. First off, I live in CA. Now, if I were to run away and travel around the country, would people be looking for me nation-wide? If I used my military ID (my step-dad is retired military) in any of the 48 states, could I be arrested and brought back to my parents? When I turn 18, will I still be considered a runaway? Could you also provide information about any laws pertaining to running away? Thank you!