First person: I
Ex.: "I was surprised to find that mice had eaten my pocketwatch. I began my campaign to eliminate their unwanted hordes immediately."

Second person: you
Ex.: "You were surprised to find that mice had eaten your pocketwatch. You began your campaign to eliminate their unwanted hordes immediately."

Third person: he, she, it
Ex.: "He was surprised to find that mice had eaten his pocketwatch. He began his campaign to eliminate their unwanted hordes immediately."

Still don't understand second person? Most people don't, apparently. It's not first, it's not wrong, and it really does exist. Go read Bright Lights, Big City. Go back and read the Choose Your Own Adventure books, even. Go read Diary, fer cryin' out loud.

These are the basics.