There are quite a few. You can try looking on fanfiction websites like Archive of Our Own. There, you'll likely find numerous stories centered around the Cullens all loving Bella. Just search for relevant tags such as 'Cullens', 'Bella', and 'love' to narrow down the results.
A common theme is the struggle with the supernatural and human relationship. Since Bella is human and the Cullens are vampires, there's often the theme of how they bridge that gap. Another theme could be jealousy among the Cullens as they all vie for Bella's affection in different ways.
Obviously, Bella and the Cullen family are the main characters. Bella is the adopted one. The Cullen family includes Edward, who has a special relationship with Bella, Carlisle who is like the father figure, Esme the motherly figure, and the other Cullen siblings like Alice, Jasper, Rosalie, and Emmett.
Well, it could involve Bella adjusting to her new life with the Cullens. Maybe she has to learn their unique family rules and deal with the fact that they are vampires. She might also face challenges from other vampires or supernatural beings who don't like the Cullens taking in a human.
Obviously, Bella and the Cullens are the main characters. Bella is the human who enters the world of the Cullens. And the Cullens include Edward, who has his own complex personality and abilities as a vampire. Then there's Alice, who might be able to see the future and plays an important role in Bella's interactions with the family.
Well, perhaps Bella discovers that the Cullens have been lying to her all along about their true intentions. Maybe they were using her for some ulterior motive, like protecting their vampire secrets from other threats in a way that betrays her trust.
There could be other vampire clans that see the Cullens' camping trip with Bella as a threat or an opportunity. They might try to disrupt their time in the woods. Another possibility is that some shape - shifters in the area don't like the presence of vampires and decide to cause trouble.
Well, they might encounter some unique supernatural creatures in the woods. Since the Cullens are vampires, there could be other dangerous beings that are attracted to their presence. Maybe they'll have to protect Bella from these threats.
One possible interesting plotline could be Bella's adjustment to her new family life with the Cullens. She has to adapt to their unique lifestyle, which might include things like their dietary habits and their nocturnal activities.