A few fertile topics for writing:
A ritual—wedding, funeral, graduation, christening, bris. People come together, emotions arise, relationships change or are cemented or something in between.
A transition—starting high school or college, a move, retirement, a new job, divorce. Leaving one world for another.
A surprise—news of an affair, a financial mistake or setback, a long-held secret revealed, contact from a birth parent or unknown sibling. How did you handle it?
Illness and death. These are, of course, transitions, too—and usually surprises. But they deserve their own category.
An animal enters your life. This has been done a lot. An animal departs your life. Ditto—and wrenching. So make it new.
Reflect on an abstract topic—a genre with a long history going back to antiquity. The subject could be loyalty, indecision, generosity, hatred, memory itself . . . . Carve out a take based on your experience and point of view. Be a philosopher who earns that role by telling really good stories.