It's highly unlikely that the characters in 'House of the Dragon' would actually watch fanfiction about themselves. Fanfiction exists in our world, created by fans for fans, and the characters in the show are fictional entities within their own fictional universe. They don't have access to the fan - created stories about them.
Yes, there are. For example, Freddie Mercury. His life story is filled with real events that inspired the music and the legend of Queen. His upbringing, his struggle with his identity, and his rise to stardom are all real - life elements that contributed to the Queen story.
I'm not sure specifically as this seems like a rather strange and unheard - of story title. It could potentially be about some wild experiences on a tour bus involving rockstars, but without more context it's hard to say.
One possibility could be a science fiction graphic novel where scientists save the world with their groundbreaking discoveries and become heroes, thus being seen as rockstars.
Freddie Mercury. His story is remarkable. He was born in Zanzibar and came to England. He formed Queen and their music became iconic. He had an incredible stage presence and a unique voice. His battle with AIDS while still creating great music is a tragic yet inspiring part of his story.
Definitely not a true story. House of the Dragon is a work of imagination and creativity. It weaves a complex tale of power, politics, and dragons within a fictional realm.