He might face distrust from some members who are cautious about his connection to Voldemort. Since Harry has a unique bond with the Dark Lord, some in the Order could be worried that he might be used as a tool against them.
Some members may be immediately welcoming and eager to assist. They recognize Harry as an important figure in the fight against Voldemort and understand his need for support.
In some fanfictions, Draco might help the Order by providing inside information from the Death Eaters. Since he's from a Death Eater family, he could have knowledge about their plans or movements.
In the fanfiction, Snape could be in a really tough situation when Harry comes to him for help. On one hand, he has his loyalty to the Dark Lord (or at least that's what others think), and on the other, there's this boy who is the son of the woman he loved. He might end up guiding Harry in a very roundabout way, like giving him a potion ingredient that has a hidden meaning or leading him to a certain book in the library that contains the solution to Harry's problem.
The snake might use its ability to move stealthily. It could spy on the enemies for Harry Potter. For example, it can slither into hidden places where humans can't easily reach and gather important information.
One challenge could be dealing with other students who don't understand his over - protective attitude towards Harry. Some might think he's being too nosy or interfering. Another might be that he has his own studies and responsibilities at Hogwarts which could sometimes conflict with his protection duties.
Maybe he has read some really bad Order fanfictions before that were full of inaccuracies. For example, the characters' personalities were completely distorted or the plot was so far - fetched that it made him lose trust in all Order fanfictions.
Maybe in the fanfiction, the Order has some actions that Harry disagrees with. For example, they might be too controlling over his life and decisions. Harry is a very independent person, and if the Order tries to restrict his freedom in the story, it could lead to his hatred.
Perhaps Harry discovers some dark secret about his own past or powers that he thinks only Voldemort can help him understand. For example, if he finds out that his connection to Voldemort is more complex than he thought and that Voldemort holds the key to unlocking or controlling certain aspects of his own magic.
Harry Potter and the Order of the Phoenix was released in the United States on September 10, 2001.
In some fanfictions, Harry might initially be angry and feel betrayed when he confronts the Order. He could question their decisions and secrecy. For example, he might be frustrated about not being fully informed regarding the plans against Voldemort.