Goku might run into past versions of his friends. He could see a younger Krillin or Bulma and have some really interesting interactions. He could also meet past versions of his enemies and try to change their fates. For instance, he could meet a young Vegeta and try to steer him away from the path of evil. This would be a huge change in the Saiyan's story.
The following are some recommendations for time-travel novels:
1. Ugly Doctor: This is a story of a counterattack in which a doctor grows medicine and becomes rich.
2. " Feng Hua of Generals ": This was a classical fictional story of a girl who was reborn from time travel and a girl who was reborn from time travel.
3. [Evil Woman in Power]: This was the story of a reborn woman who cleansed herself and lived happily for the rest of her life.
4. " Qingyun Terrace " Shen Xiaozhi: The male protagonist has a noble identity and has strategies and means. The female protagonist has a firm heart and superb martial arts skills. The story begins with the collapse of Qingyun Terrace and ends with the reconstruction of Qingyun Terrace. The plot is closely linked.
These novels were all about time-travel. Each story had a unique plot and character setting, suitable for readers who liked this kind of theme. Please read according to your interests.
The following are some of the recommended novels:
1. "Coincides with the Rain" Author: Shen Xiaozhi
2. A Red Apricot Paper in Spring Author: Xu Chengyue
3. "Laughing Spring Breeze" Author: A Copper Coin
4. [The Coroner's Wife]
5. Futu Tower Author: Fourth Sister You
These novels were all authentic ancient novels. There were no elements of transmigration, rebirth, or golden fingers. They were suitable for readers who liked pure ancient stories. Please note that due to the limitations of the search results, there may be other novels that meet the criteria that have not been mentioned.
In the fanfic, Goku could become friends with Naruto easily. Since they both have a strong sense of justice and a will to protect their friends. Goku might teach Naruto some of his training methods, like training under heavy gravity. And Naruto could show Goku the unique aspects of ninja villages and how they function.
Vegeta would also be an important character. His rivalry with Goku would intensify even more. Seeing Goku achieve the Super Saiyan form early would fuel his jealousy and his desire to become stronger. He might even try to find new ways to train or gain power to catch up with Goku.
Well, he could change a lot of things. Maybe he'd prevent some of the big battles or save some characters who died. For example, he might stop Frieza from destroying Planet Vegeta earlier. It would be a whole new timeline with different outcomes.
Perhaps in the fanfiction, Goku goes Super Saiyan early due to some special training or a unique emotional trigger. It could be that he witnesses the death of a different character, like Krillin, much earlier than in the original story. This extreme emotional distress causes him to break through his limits and transform. As a result, the Saiyan saga would take a different turn. Frieza might become aware of Goku's new power much sooner and plan different strategies to deal with him.
Well, he could change a lot of things. Maybe he'd prevent some of the big battles or save some characters who died in the original timeline. For example, he might stop Frieza from destroying Planet Vegeta earlier. It would also be interesting to see how his Ultra Instinct powers interact with the past events and characters who haven't seen such power before.