Complex sentence: As a teenager herself, she was a firm believer that the beliefs and ideas held by young people were just as important as those held by adults and the song reminded people of this and also that the current youth would become the next generation of adults.
Split into simpler sentences: As a teenager herself, she was a firm believer that the beliefs and ideas held by young people were just as important as those held by adults and the song reminded people of this. It also reminded them that the current youth would become the next generation of adults.