What are the aspects of good and bad conduct in this situation which ended with the breaking of glasses and the reprimand of the boy and the girl?

You did well in condemning the evil and in your anger for the sake of Allah, and you mentioned the verses and hadiths that encourage enjoining good and forbidding evil. However, you erred by breaking the person's glasses. Enjoining good and forbidding evil must not involve destroying people's property without right. Therefore, you must guarantee the value of the glasses or repair them. If you cannot reach their owner, then give their value in charity on his behalf. We advise you to accompany righteous youth who are zealous for the religion of Allah.