Naruto would likely become more self - reliant. As a ronin, he doesn't have the support of a village. So during the Chunin Exam, he has to trust his own instincts and skills more. He may also become more cautious as he realizes he can't always count on backup.
Maybe he realizes the exam is too dangerous or he discovers some unfairness in it. In the original Naruto story, Naruto has faced many difficulties and moral dilemmas during the Chunin Exam. So in the fanfiction, similar situations might push him to quit.
He might become more determined. After failing, Naruto could realize his weaknesses and be more eager to improve. He may start training harder than ever, focusing on the areas where he lacked during the exam.
He might face disappointment from his friends and mentors. His friends who were also participating in the exam might feel let down, and his mentors, like Kakashi, could be concerned about his decision and how it will affect his future as a ninja.
When Naruto passes the Chunin Exam in fanfiction, his confidence would soar. He'd start to see himself as more of a capable ninja. He might become more of a leader among his peers, as passing the Chunin Exam is a sign of growth. For example, he could start giving advice to younger ninjas.
One possible storyline could be a ronin Naruto having to prove himself in the Chunin Exam despite not being part of a regular ninja village. He might face discrimination from some of the other participants who view him as an outsider. Another could be Naruto using his unique experiences as a ronin to develop new and unexpected ninja techniques during the exam.
The story could develop in a way that Naruto's friends try to cheer him up and convince him to re - enter the exam. They might show him how much they believe in him and that his giving up is not the solution. For example, Sasuke could tell Naruto that he needs him as a rival to become stronger. Another development could be that Naruto starts to train secretly and then surprises everyone by coming back stronger later in the exam.
One possible reason could be that Naruto faced an extremely tough opponent in the exam. Maybe the opponent had some special jutsu or skills that Naruto couldn't counter at that time. Another reason might be that Naruto made a critical mistake during the exam, like being overconfident and underestimating his enemy.
One possible scenario in such a fanfic could be Naruto easily overpowering his opponents during the Chunin Exam. For example, in the written test, he might use some new, godlike power to read the minds of the examiners or sense the correct answers. During the combat rounds, he could defeat his foes with a single move, leaving everyone in awe. His newfound power might be related to some ancient ninja art he discovered or a special training he underwent secretly.
One possible fanfic could be about Naruto and Temari teaming up during the Chunin Exam in unexpected ways. Maybe Naruto helps Temari when she's in a tough situation against an opponent she underestimated. They could form an alliance that surprises everyone.
Naruto may become more confident. By raising his hand, he's taking initiative, which is a sign of growing self - assurance. He's no longer waiting for others to pick him or tell him what to do.