Harry potter and the cousin of the boy who lived

What changes would a fan of harry potter bring when he finds himself in the body of a eleven year old cousin of harry potter (not Dudley) will he follow the canonical story or will he change the story for the better or worse only time and fate can tell.

The Protag will be the son of twin sister of Lily M. Potter who will replace Lily as the godmother of Luna and this will be an AU world with a few differences nothing big but a few that are important for the protag to be born.

This is my first time writing a FanFic(not that kind of fan fic) hope you guys and gals like it.
Its just a side project to unwind while i stress over my projects for University that i need to do.

Disclaimer - I do not own the characters and the plot of the Harry Potter Universe.