Colleges want to learn about you - what makes you unique. My son is an only child and many of his friends are. There is nothing unique about that.
You don’t have to write about something amazing - just look on the essay as your chance to show the schools who you are and what makes your unique. When my son applied to UCLA and Berkeley, the application required two personal statements (they have changed since). Formerly prompt 1 was “Describe your world and how it has shaped you”. My son wrote about his interest in math and science and how his school only had one science related extracurricular, First Robotics. He was hesitant to join because it involved things like power tools, welding and other tech skills he had no aptitude for. He wrote about how he went from only knowing how to hold a wrench to leading the electrical team.
The second prompt was “Tell us about an accomplishment that made you proud and relates to the person you are” (I’m paraphrasing, the actual prompt is not that important and he reconstructed both essays to fit the common application essay). He wrote about how he had played trombone in jazz band for 6 years and how his favorite part was the intellectual and technical challenge. However, this approach became a problem as the more advanced jazz bands expected the players to be able to extemporize and play original solos on the spot. His struggle to translate his proficiency in music theory and technique into emotional and creative musical expression and how he finally achieved this goal was both humorous and a great insight into the person he is.
He was accepted to USC and was awarded the Presidential Scholarship (half-tuition). When he met the scholarship interview committee they said, “Oh, you’re the kid who wrote the great essay about playing trombone”.
Just for practice, pick one unique memory about something simple like food and write an essay about it. You will be surprised how the ideas can start flowing. If you don’t think food can be a great essay topic, my son’s girlfriend got into Stanford (she was a fantastic student in all ways) and her essay was about her memories of making tamales at Xmas with her grandmother, a woman who worked in the fields picking strawberries. I actually cried when I read the essay, it was so thoughtful about her Hispanic background and how it shaped who she is.