"Autobiography" means a biography of oneself, that is, the author is describing their own past and their own life.
When you describe your own life, typically you would write it in the first person ("I") and this is also true for Barrio Boy.
I think I can give maybe some guidance on number two but you’ll have to write it yourself and answer number three yourself. So when they say tell the truth, the whole truth, and nothing but the truth I believe what they want is simply the truth, the whole truth which means no leaving out details tell EVERYTHING, and nothing but the truth means to just not lie. I really hope this helped even a little bit!
