Sure, it is. Dork Diaries is in the realm of fiction. It weaves fictional tales that often involve the adventures and experiences of the main characters in a fictional setting.
It depends. Some parts of Dork Diaries can feel realistic, like the characters' emotions and school experiences. But there are also elements that might be a bit exaggerated for entertainment.
The main character is Nikki Maxwell. She is the one dealing with all the frenemy situations. Then there are her friends like Chloe and Zoey, who are important parts of her social circle at school. And of course, there are the characters who sometimes act as enemies, like Mackenzie Hollister, who creates a lot of drama for Nikki.