I think the teacher wants you to write about something that poses a problem in real life and needs a good solution. She/He wants you to use a problem with an existing solution, but they want you to write about if the solution is good or if its bad and what should have been done instead.
Hope this clarified the prompt up! Look online for topics/issues you're passionate about! :)
The main idea of the song Mean by Taylor Swift is that by being mean, one doesn't succeed in life. It just hurts others, and in the end, those people could be doing way better than the people who are being mean. Don't stop pushing forward because of what others say. To find a main idea of a song, look closely at lyrics. Try find repetitive phrases or keywords. Hope this helped. :)
