The main characters are Aladdin, of course. He is the protagonist, a poor young boy who discovers the magic lamp. Then there is the evil magician. He is the one who tricks Aladdin into getting the lamp for him at first. And the princess is also a main character. She is the object of Aladdin's love and they end up getting married.
One of the main themes is the power of magic. The magic lamp in the story brings great power and wealth to Aladdin. Another theme is rags - to - riches. Aladdin goes from being a poor boy to a wealthy and powerful figure. Also, there is the theme of good versus evil, as Aladdin has to face the evil magician who tries to take the lamp back from him.
In the original story, Aladdin's first wish is to be saved from the cave where he finds the lamp. His second wish is often to become a prince so that he can marry the princess. And his third wish is usually to free the Genie from the lamp.