I wonder what kind of người hâm mộ Fiction to write...

Well, if you're a new người hâm mộ fiction author, I'd suggest picking the nguồn material you're most familiar with, and nghề viết văn about it in canon style. It's simpler than alternate character interpretations, OCs, AUs, and anything else deviating (radically hoặc otherwise) from the original source. It's also likely to garner less hate, even if it isn't incredibly original. Just don't rip off an existing episode.