Well, Goku is a Saiyan, and Saiyans have a strong sense of family deep down, even if they don't always show it. When he meets his parents in this fanfiction, he could initially be in disbelief. But once he realizes it's real, he would embrace them wholeheartedly. He may even start to show off his strength and skills a bit, like a child showing off to his parents. And he would be excited to hear stories about their Saiyan race and how they ended up in the situations they did.
He would be extremely excited. Goku has always been curious about his parents, so he'd probably have a big smile on his face and lots of questions to ask them right away.
They likely have a loving relationship. As Saiyans, they would have a bond based on their race and their shared goals, perhaps related to the Saiyan pride and survival.
His father might be extremely proud. After all, Goku has achieved so much, like protecting the Earth multiple times. He would look at Goku with admiration for his strength and kindness.
Goku's reaction could be a mix of shock and joy. On one hand, he has been on Earth for so long without any real family connection to his Saiyan side. When he sees his parents, it would be overwhelming. He would likely be in awe of his father, Bardock, given his father's reputation as a strong Saiyan. And he would be eager to bond with his mother, who he has never known. He might also feel a sense of belonging that he has been missing all his life.
Well, Vegeta would be a likely character. He might be initially suspicious of the female Goku. Maybe he thinks she's a threat or just can't believe there's another Goku - like being. He could be there to add some comical moments as he tries to understand the situation.
In general, it's a bit of a toss-up. The strength of Manga Goku and Anime Goku can vary depending on the specific arcs and battles. Sometimes, it might seem like one is stronger in a particular situation, but that could change in another.
Obviously, Goku is the most important character. Then his parents, Bardock and Gine. Bardock was a powerful Saiyan warrior, and Gine was a kind - hearted Saiyan. There might also be other characters like Goku's friends on Earth who could be involved in the story in some way, for example, they could be witnesses to the reunion or help Goku's parents adjust to life on Earth.