Who can teach me more about Morphy defense ? Thank you

Perhaps it would be helpful to look at Starting Out: Ruy Lopez by IM John Shaw (2003).
https://web.archive.org/web/20140627024240/http://www.chesscafe.com/text/hansen53.pdf

I posted a book excerpt of a limited discussion of this defense at:
https://www.chess.com/forum/view/chess-openings/is-the-ruy-lopez-a-lie?lc=1#last_comment