Answer:
I won't write it for you but I will help you with a few tips!
1. Express the meaning of what free is to you. I assume the assignment isn't meant for you to just throw up words onto a paper but for them to have meaning. Try to connect with yourself and paint out the picture of freedom with words and phrases that complete that picture.
2. Some songs get far without rhymes, although rhymes help you get creative with words and sometimes end up with a better message displaying your idea of being free.
3. If you are going to sing this song, try to sing it in a clear higher tone because usually songs with lower tones seem more threatening or less expressive. Sing with passion.
4. listen to non-lyric music that seems breezy or calm while you make it or just imagine a beat in your head. This will help you come up with lyrics because it will guide your brain into the type of theme you are going for, keeping you in that mood and sometimes making you more productive.
Hope this helps! And trust me it will feel more rewarding than taking someone else's idea of being free.
Step-by-step explanation:
You got this :D