That’s asking a lot. Your assignment, that is, not you. It’s one of the basic story structures and a very classic one. Trying to write a story that does all that and does it well is the task of a legion of writers and wannabes. Yet some children’s picture books accomplish it in a few hundred words and some massive tomes do not.
Choose a setting in time and space. Real world, here and now? Your city, your school, your household? Imaginary world, past time, realistic, magical, historic, future?
In that setting you have a character who needs or wants to get something or accomplish something. That’s the quest. Try “what if”? questions to get you there: what if a prince fell in love with a princess and her father wanted to test his worthiness before consenting to a wedding? what if a boy with no money but a passion for art wanted to see some of the world’s most beautiful paintings? what if a girl of the future needed to come back to the present to find the answer to a question that holds the key to her life’s mystery? what if a little puppy wished he could fly like a bird?
There are obstacles in the way of accomplishing that goal. What are they? Attacking them is the adventure.
In the process, the character grows somehow: discovers the meaning of friendship, or learns that kindness begets kindness, or finds out he has strengths he didn’t know he had, or learns that bullies are really cowards, or sees the cost of lying, or turns a weakness into a strength, or discovers “there’s no place like home,” or some other thing that you yourself have learned and can think of a way to illustrate dramatically in fiction.
Good luck.