Can someone me,
1. define teen dating violence and include details about the abuse of power in a relationship.

Teen violence in a relationship can show up in many ways. Someone in the relationship may try to control the other person by what they wear, when they go out, who they talk to. Violence can also be shown by physical violence to the other person in the relationship. And since it is with teens the person being abused may not always try to get out of the relationship or think it is "normal".

An epidemic is a large and localized outbreak of a sickness or disease.  a pandemic is a large global outbreak of a sickness or disease.