In the fanfiction, perhaps it focuses on the initial spark between them. It might show how Vegeta, with his tough exterior, starts to soften a bit when he's around Bulma. For example, he could start to notice small things about her, like the way she furrows her brow when she's thinking hard about something in her lab, and that starts to draw him to her.
In the original, their relationship develops gradually over time. But in the fanfiction, it could speed things up. For instance, they might have a more immediate connection, like falling in love at first sight instead of the slow - burn we see in the official story.
He could also become more strategic. Time travel would expose him to different situations and enemies. He'd need to plan better and think ahead. Maybe he travels to a time when the Z - fighters are all defeated, and he has to figure out how to prevent it. This would make him less impulsive and more of a long - term thinker.
At first, it might be a relationship based on mutual need. Vegeta needs Bulma's resources and intelligence to get back on his feet, and Bulma is intrigued by this alien. As time passes, they start to understand each other better. For example, Vegeta may start to open up about his past and his Saiyan pride, and Bulma will share her dreams and ambitions with him.
Obviously, Goku would be a main character he'd interact with. If he goes back to when Goku was a kid, he could train with him, or try to convince Goku's grandpa to let him train Goku in a different way. Another character would be Bulma. If he goes back far enough, he could meet a younger Bulma and perhaps change their relationship dynamics. He might also interact with his younger self. This could lead to some really interesting self - reflection and growth as he tries to guide his younger, more hot - headed self.
The time machine in the last episode of the first season of The Flash was a fictional element that appeared in the plot, not a real physical machine. In the plot, the Flash and Wally West (Vera--->Veracity) discussed a device called the "time machine" while discussing future technology and time travel.
According to the plot, a time machine was a device that could travel through time and change the course of history. However, in reality, time machines were not real physical machines but a fictional concept of technology.
In the first season of The Flash, Reverse Flash was an existence called the "Child of Time" and one of the creators of the time machine. The purpose of Reverse Flash was to train the Flash to master the power of the time machine to achieve time travel and change history. However, in the plot, the plan to reverse flash was foiled by Wally West and the Flash.
Often, in fanfiction, a common plot is that Naruto uses the Final Flash to save his friends in a dire situation. Maybe his friends are trapped by a powerful enemy's jutsu, and the only way to break through is with this powerful attack. It could also be a plot where Naruto teaches the Final Flash to one of his students, like Boruto, and how that changes the new generation's fighting capabilities.
I don't think there's a sequel. Comics often depend on various factors like popularity and the creator's plans to determine if a sequel will be made, and it seems that for Flash First Steps, a sequel hasn't been announced or produced yet.