Let's say I was about to start a fresh story that's meant to portray my culture. To do so, I'm going to pull what I can, what was most remarkable, from my experiences of all kinds.
For me, this involves the books I've read, the stories I was told. For another person it might involve the music they heard, the instruments used here, the lyrics, the styles of past musicians. For yet another person it could mean the sceneries, the landscapes, descriptions of what it feels like to be there. For another person it could be something far more specific, like capturing what it was like to grow there, how life was like as a child in this particular environment, what their home was like. Or, while talking about a place, you can also talk about other places and how they compare to it, exploring your experience in only having live in the first one for a limited time.
I believe that creating art about a culture, your culture, is not the kind of thing you can follow a recipe for. I think you should approach it as a bit of an improvisational exercise, using what you have on hand and what is most meaningful to you. In your case, going only from what you told me in your question, I'd suggest you try and remember as much as you can about the time you spent immersed in your culture and write it down as bullet points. Don't worry about not remembering big and important things. Instead, take note of what daily life was life. How food tasted, how people talked, the sounds of your home, what school was like, what friends (or lack of them) were like, what media you were exposed to, whether you felt like you were fitting in or not, your insecurities and your happiest moments, so on.
Take note of all those things which are very particularly yours, which meant something to you, then take a step back. Look at all of it from a distance and then let yourself feel which ones you'd like to explore the most.
To bring a very real comparison, the idea for the flooded town in the hinterlands came from watching a movie when I was 9 or 10 in school. I couldn't even remember what the movie was called, I couldn't find it, but that was a spark that led me to adding that element to the story. The idea of the hinterlands being infested by butterflies came from my father having to drive through many swarms of them when we went there on a trip. Moths bringing good luck is a superstition my mom told me about.
If I had to make a list of the most important things in the real life hinterlands, none of those things would be there. But they were remarkable to me, and I could extract meaning out of them.
You can do the same. Gather your ideas, then select which ones feel the most resonant and dive deeper into them. Do some research on those points in particular. Be emotionally honest with yourself and see how those things, including the brief time you spent in your culture, make you feel. Take note of what insecurities pop up, what makes you uncomfortable, and try to be your own therapist in order to crack what's going on. Gather all of those things, the good, the bad and the personal, and make your collage of your culture.
It doesn't have to be a 1:1 representation of reality. What matters the most is making it meaningful and very intellectually honest. Writers can only do so much to capture a complex reality in writing, and people can rightfully criticize us for not getting things right, but that doesn't matter so much when there's a great deal of honesty there. It speaks louder.