An interesting pairing for this assignment would be "Sonny's Blues" by James Baldwin and "Mother to Son" by Langston Hughes. (Both are linked below.)
Here are some commonalities you could discuss:
Theme: Both focus on overcoming adversity. In "Sonny's Blues," the narrator finally finds a way to empathize with his brother Sonny's drug troubles after he loses his own infant daughter, and he finally opens himself up to supporting Sonny's dream of creating music. In "Mother to Son," the son (to whom the poem is addressed) has stumbled into unknown troubles and is given encouragement by his mother, who has seen troubles of her own.
Characterization: The son in "Mother to Son" is ready to give up. Whatever trouble has found him, he is so despondent that his mother feels compelled to tell him, "Don't you set down on the steps / ’Cause you finds it’s kinder hard." Likewise, Sonny has nearly reached the end of his rope, writing to his brother, "I feel like a man who's been trying to climb up out of some deep, real deep and funky hole. . ." Both characters are left feeling quite desperate during the troublesome parts of their lives.
Tone: The tone shifts in both the poem and the story, but overall they resonate a tone of hope. The mother is hopeful that her son can overcome his troubles because she has proven herself strong and knows that he can overcome his own "dark" places "where there ain't been no light." Through Sonny's music, the narrator learns of the way music can connect his and Sonny's histories; he reflects that "freedom lurked around us and. . .he could help us to be free if we would listen."
Differences: Because the speaker in "Mother to Son" is the troubled son's mother, she feels more authoritative in telling her son to basically get his act together. Her tone is more forceful and she doesn't beat around the bush regarding the path her son needs to take. The brothers in "Sonny's Blues" have lost their mother, and the narrator really struggles to find the right approach to use in helping his younger brother. He loses contact with him altogether for a period of years, and Sonny's life deteriorates in the process.
The thesis for your paper could be something like this:
Langston Hughes's poem "Mother to Son" and James Baldwin's story "Sonny's Blues" share similar themes, characterization, and tone, but they differ in the authoritative role which the narrator takes.
I hope this gives you some ideas for getting started on this topic. Good luck!