Since I haven't read the 'read along rocket story', it's difficult to determine. They might be a team of space explorers, or perhaps a young boy or girl who dreams of going to space and gets to ride in the rocket in the story.
Well, without having read the 'read along rocket story' myself, it could be centered around a rocket journey. Maybe it tells the story of a group of astronauts or space - exploring beings. It might include details about the rocket's launch, what they encounter in space like strange planets or alien life forms, and how they overcome difficulties during their voyage.
Most likely, Thomas the Tank Engine is one of the main characters. He is usually the central figure in stories related to this series.
There are also Cinderella's stepmother and stepsisters. The stepmother is cruel and jealous of Cinderella's beauty. The stepsisters are vain and unkind, always trying to make Cinderella's life difficult. And then there is the prince. He is the one who falls in love with Cinderella at the ball.
Wendy, her brothers John and Michael are important characters. They are the ones who go to Neverland with Peter Pan.
Snow White, the evil queen, the seven dwarfs, and the prince.
The main characters are the mouse and the Gruffalo. There are also other animals like the fox, the owl and the snake.
The main characters are the fox and the hound.
The main characters are the little mermaid and the prince.
In the 'the jungle book read along story', Mowgli is the central human character. He is surrounded by various important animal characters. Baloo, the friendly and carefree bear, is like a mentor to Mowgli at times. Bagheera, the intelligent panther, is another key figure who helps Mowgli navigate the jungle. And then there's Shere Khan, the menacing tiger who is often in conflict with Mowgli and the other jungle dwellers.
Scar is another main character. He is Mufasa's jealous brother who causes a lot of trouble in the story. And of course, we can't forget Timon and Pumbaa, Simba's fun - loving friends who help him during his exile.