It's not common at all. People usually read novels in a normal way, like holding the book and turning pages gently. Biting a novel might be seen as strange or unhygienic behavior.
One common theme is forbidden love. Since the Vampire Knight world has a strict divide between vampires and humans, many fanfictions explore the relationships that are considered taboo. For example, a vampire falling in love with a human and the challenges they face because of it.
One interesting Vampire Bite Fanfiction could be about a human who gets bitten by a vampire and then discovers they have special powers. For example, they might be able to see the future or control other vampires. Another could involve a vampire who is conflicted about biting a human he has fallen in love with.
One common theme could be the power dynamic. The vampire, being a powerful and often alluring creature, has a certain power over the bitten character. This power play can add an interesting layer to the story.
I don't know the specific main characters in 'First Bite Vampire Love Story' as I haven't read it. But usually, there would be a vampire character, probably male or female, who is the love interest. And there would be a human character as well, who gets involved in this vampire - centered world.
I'm sorry, I haven't actually read 'First Bite Vampire Love Story' so I can't give you the exact plot. But generally in a vampire love story, there might be a human who falls in love with a vampire. There could be a lot of drama around their different natures, like the vampire's need for blood and the human's mortality.
I'm not sure exactly as I haven't read it. But generally, a vampire novel set in West Hollywood might be about the vampire society in that area, their relationships, and perhaps their interactions with humans.