One possible plot could be Vegeta training with baby Bulla. He could be teaching her the basics of combat in a gentle yet firm way. For example, showing her how to throw a proper punch or dodge an attack. He might also tell her stories about their Saiyan heritage during breaks in the training.
Well, an interesting interaction could be when Vegeta first holds baby Bulla. His tough exterior softens as he looks at this tiny being. He might mutter something like 'You will be strong, little one.' Another could be when Bulla starts to cry and Vegeta tries to figure out what's wrong. He's used to dealing with battle situations, not a crying baby, so it's a bit of a comical yet heartwarming scene.
Another idea is that the baby's birth brings a new hope to the Saiyan community. In a world where there are threats still looming, the arrival of this child could symbolize a new beginning. Goten and Bulla could then be on a mission to raise the baby in a way that it can one day lead the Saiyans to a better future.
I'm not entirely sure specifically what a 'beerus raps beerus fanfic' is about without more context. It could potentially be a fan - created story where the character Beerus is rapping. Maybe it involves Beerus expressing his thoughts, his powers, or his experiences in the form of rap within the context of a fan - made fictional narrative.
They would become more responsible. Their relationship would no longer just be about their own feelings and desires. Now they have a child to think about, so they would have to work together more closely.
Goten could be a great addition. As Bulla's brother, his relationship with Bulla can add an interesting family dynamic to the fanfiction. Also, his Saiyan powers could interact in unique ways with Naruto's ninja skills.
You could try looking on fan - fiction websites like Archive of Our Own or FanFiction.net. They usually have a wide variety of fan - created works, and there's a good chance you might find a 'beerus raps beerus fanfic' there.
Bulma would likely be a main character. As Bulla's mother, she would play a crucial role in guiding and supporting Bulla through this new stage. She could share her own experiences and wisdom with her daughter.
Beerus would likely be more powerful. He is a god of destruction in his own universe with incredible cosmic powers. Naruto is extremely powerful in his world, but his power is mostly based on chakra and ninjutsu, which is on a much smaller scale compared to Beerus' ability to destroy planets with a flick of his finger.
Well, in Goten and Bulla kiss fanfiction, it's often about exploring a different side of their relationship. Maybe it's a moment of unexpected romance. Writers might be trying to show a deeper connection between them that wasn't fully explored in the original series.