I'm not sure as we don't have much information, but it could be a young adventurer.
Since I haven't read the 'a whole new world novel', it's hard to say who the main characters are. However, in many novels about new worlds, there are often characters who are curious and brave. They might be the ones who lead the exploration of the new world. It could be a group of friends or a single individual with a special gift or purpose that drives them to discover what this new world has to offer.
Sometimes, it might introduce new characters along with the familiar ones. For example, if it's a fanfiction based on a superhero story, the main character from the original might be joined by a new sidekick they meet in their new life. This new sidekick could be a local from the new place they end up or someone else in a similar situation as them. They could then form a bond and go through adventures together.
I don't know for sure, but they could be ordinary people thrust into extraordinary situations in this new world.
Since we don't know the specific 'new world story', it could be anyone. It might be a young adventurer, a scientist, or a group of survivors.
Since I don't know the exact story, it could be a group of children with different personalities. There might be a brave leader - type character, a smart and curious one, and perhaps a shy but kind - hearted child.
Well, in the 'New World Symphony Story', Antonín Dvořák is the central figure. But you could also consider the unnamed musicians and performers who have brought this symphony to life over the years. They are important in the sense that they help to communicate Dvořák's vision and the story within the music to the audience. And also, the people of America, both the Native Americans and African - Americans whose music influenced Dvořák, could be seen as part of this story in an indirect way.
There might be a young and brave protagonist, perhaps a new intern at the park who has a special connection with the dinosaurs. Alongside, there could be an experienced veteran who has been through all the chaos in the previous Jurassic World events. And of course, there could be some antagonists too, like poachers or unethical scientists who are causing trouble in the park.
There's no way to be certain without more information about the 'seal new world story'. However, if it's about a seal - centered new world, then the main characters are probably different types of seals, such as the harp seal, the elephant seal, etc. There might also be other sea creatures that play important roles in the story.
I'm not sure as we don't have much information. But it could be a group of explorers.
One of the main characters is John. He is an outsider who was born outside the highly controlled society and has a different set of values compared to those in the 'Brave New World'.