Maybe a fanfiction where Lylla gets kidnapped and Rocket has to use all his skills and enlist the help of his friends to rescue her. This could show his determination and love for her.
The origin of Rocket Raccoon is quite interesting. He was created on Halfworld, where he endured various experiments that gave him his unique abilities and personality. His background is filled with adventure and challenges.
Next, create the setting. Are they on a spaceship, a strange planet, or in a spaceport? The setting can add a lot of flavor to the story. If they're on a spaceship, you can describe the cramped quarters and how they interact in that limited space.
Rocket Raccoon is from a place called Halfworld. He was genetically and cybernetically enhanced. He was created as a kind of caretaker on Halfworld, which was a planet - like asylum for the mentally ill. He was given intelligence and skills to deal with the various problems there.
One common theme is his backstory. Writers often explore how he became the character we know, his time before joining the Guardians of the Galaxy. Another theme is his relationships, like his friendship with Groot or his interactions with the other Guardians.
Rocket Raccoon has a sad story. He was created through cruel experiments. He was taken from his home and turned into a weapon or tool by those unethical scientists. He was alone in a world that saw him as a freak. His only friends were those he found along his adventures like the Guardians of the Galaxy, but the memories of his past torment still haunt him.