He may be confused at first. Fanfics can be very different from his real experiences. He might wonder why people write such things about him and his world.
Well, Harry Potter is a rather humble character. He might initially feel a bit embarrassed to see himself as the center of so many fictional stories created by fans. If the fanfic portrays him as a hero in new adventures, he would probably be honored. However, if it misrepresents his friends or the values he holds dear, he could be a bit indignant. He would likely approach it with an open mind but also with a sense of protectiveness towards his own story and those he loves.
There's a chance he'd be inspired. The stories of the Naruto characters' determination and growth in the fanfiction could stir something in him. He might think about his own journey as a wizard and how he can further develop his skills and character, taking cues from the Naruto characters' tenacity.
Perhaps the travel agent is a bit of a troublemaker. Instead of suggesting normal wizarding travel destinations, they might try to persuade Harry to visit some off - limit or even illegal magical places. They could tell him about a secret portal to a dimension where dark magic is still being practiced freely, which of course, Harry would have to resist.
Hermione would probably be both curious and worried. She'd want to research all about Harry's half - demon nature to find out what it means and how to help him. Ron, on the other hand, might be a bit more hesitant at first. He might be a bit scared but would eventually come around because of his loyalty to Harry.
The Weasleys' reactions would be complex. Arthur, with his curious nature, might study the fanfictions to understand how Muggles view their world. Molly would likely be more conservative in her views, not liking any fanfiction that distorts the family values. The younger Weasleys would be more likely to embrace the creativity, with Fred and George looking for ideas to use in their pranks, and Ginny might enjoy seeing herself in different heroic scenarios.
He might become withdrawn. Harry has been through a lot in his life, and being heartbroken by Fleur could make him retreat into himself. He may avoid his friends and isolate in his dormitory at Hogwarts.
Hermione would be extremely curious. She would immediately start researching it, trying to figure out its mechanics and where it came from. She might even try to find a way to improve it or adapt it to the wizarding world's technology.