Jiraiya. Naruto could have a different kind of apprenticeship with Jiraiya. He could share some of his future experiences with Jiraiya, which might change how Jiraiya trains him and also how Jiraiya approaches his own missions and prophecies.
The Third Hokage. Naruto might interact with the Third Hokage in a new way. He could reveal some of the future threats to the village that the Third Hokage might not be aware of, and they could work together to strengthen the village's defenses much earlier.
Naruto would meet his younger self. This would be a really strange situation. He could also meet all the important shinobi from the past. For example, the First and Second Hokage. He might have a chance to learn from them directly, instead of just hearing about them in stories. Additionally, he could meet some of the characters who were only mentioned in passing in the original story but had a big influence in the past.
In this fanfiction, Naruto would interact with a variety of characters. First, his old friends like Choji and Kiba. They have been through a lot together and would support Naruto in the war. Then there are the leaders of the different ninja villages. Naruto might meet with the Raikage or the Mizukage. His interactions with them could range from tense negotiations to forming alliances. And don't forget about Hinata. Her support for Naruto could be a source of strength for him during the difficult times of war.
Naruto's character could develop in many different ways. If he travels to the past, he'd have to adapt to the different ways of the old ninja world. He might become more respectful of the traditions as he sees how they were formed. Also, he could become more of a mentor figure to the younger versions of his friends, which would change his self - perception from a student to a teacher, thus making him more mature and responsible.
Obviously, Naruto himself is a main character. He will be interacting with the Kyuubi. Since the Kyuubi is a powerful and sentient entity within Naruto, their interactions could be intense. Naruto might also encounter other ninja who have knowledge about the Kyuubi. For example, Jiraiya. Jiraiya, being Naruto's mentor, might appear to give advice on how to handle the situation with the Kyuubi. He could share some of his own research and experiences related to the tailed beasts.
Sasuke would probably interact differently. As a girl, Naruto might be more of an enigma to him. He could be more protective or more conflicted in his feelings towards her. Instead of just seeing her as a rival, there could be a romantic undertone in their interactions.
Naruto could also meet the previous Hokages in their prime. He could learn from them directly and perhaps even influence their decisions. For example, he might be able to convince the First Hokage to handle the Uchiha clan's situation differently, which could have a huge impact on the future (or in this case, the future that Naruto comes from).
Sasuke would be a likely character to interact with Naruto as a Time Lord. Their complex relationship in the original Naruto series would add an extra layer of drama in a time - traveling scenario. Another could be Kakashi. His wisdom and experience would make for interesting conversations with Naruto, especially when Naruto has the power of a Time Lord. And of course, Jiraiya. Given his close relationship with Naruto and his own adventurous spirit, he'd be very involved in Naruto's time - traveling adventures.
Jiraiya could also be one of the main characters. He was Naruto's mentor and had a connection with Kushina's family. He could play a role in helping them adjust to the time travel and also use their knowledge to his advantage in some ways, like getting intel on future threats.
Edward would definitely interact differently. If Bella goes back in time and changes her initial approach, Edward might be more or less intrigued by her. For example, if she's more confident, he might be even more drawn to her than in the original story.
He would gain a deeper understanding of the history and the people around him. By experiencing the past first - hand, Naruto could see the motives and the struggles of the older generations. This would make him more empathetic towards characters like Itachi. He would realize that there were many hidden factors behind their actions, and this new - found understanding could shape his character into a more mature and complex individual. His relationships with his friends and allies would also be affected as he could share this new knowledge with them.