The information you provided is not detailed enough for me to give an accurate answer. Please provide more information about the female protagonist of the vampire novel and the adoption of three sons so that I can better help you.
Typically, in 'got7 bambam vampire fanfiction', Bambam is often depicted as having enhanced physical abilities like super strength and speed, which are common vampire traits. Also, there's usually a sense of mystery around him as a vampire.
There were many novels that contained such plots. One of the more famous novels was Twilight. This novel tells the love story between the male vampire Edward and the female protagonist Bella, as well as the story of them adopting another vampire girl, Luna. There were also many other vampire novels that contained similar plots, such as Vampire Hunter D and The Vampire and the Cross.
In this fanfiction scenario, Naruto could learn a lot from the vampire about immortality. He might use this knowledge to protect his village in new ways. Also, his relationship with his friends could change as they might be a bit scared or in awe of his new vampire - related abilities.
One popular 'got7 bambam vampire fanfiction' is 'Bambam's Vampire Secret'. It has an interesting plot where Bambam hides his vampire identity from the other members at first. Another one could be 'Vampire Bambam's Love Quest' which focuses on Bambam's search for true love as a vampire.
Naruto's life would be completely different. He'd be part of a vampire family, which means different social norms and rules. He might not be able to be as open with his old friends as before. And he'd have to learn about vampire history and lore, which could be both fascinating and terrifying. His identity as a ninja would be in conflict with his new vampire identity in some ways, like when it comes to using violence. Vampires have their own way of dealing with threats that might not align with the ninja way.
I recommend the book "Douluo's Moon Pavilion Exchange Student" to you. The male protagonist of this novel is Tang Yue-Hua's grandson, the grandson of a platinum bishop, who transmigrated to Spirit Hall to learn the exchange story. I hope you like this fairy's recommendation. Muah ~😗
Some fanfics make vampires fit into the GoT world by having them be related to magic. Since there is already magic in the GoT universe, vampires could be a part of that magical ecosystem. Maybe they were created by some dark magic long ago and are now starting to surface as the magic in the world becomes more prominent again. They could have unique powers that interact with the existing magical elements in the story, like being able to resist the warging ability of some characters or having an immunity to certain poisons because of their undead state.