Think of family situations found in your own adult world and look at how teenagers in those families cope with them.
Visit places where teenagers are likely to be with parents, and notice why and how teenagers attempt to gain independence from the adults.
Study times of struggle and heartbreak in real history and imagine how the teenagers in those settings would have acted.
Hang out where teens hang out --- from baseball fields to skating rinks. Watch and listen. Notice the drama in relationships and the emotional breakdowns over all sorts of disappointments.
Volunteer at a junior high or high school and witness the stories that exist behind the scenes in the school environment.
Watch teens at their jobs in fast-food restaurants and retail shops. Pay attention to their relationships with coworkers and how they handle authority and responsibility. Imagine why they want to work --- or must work.