If you have kids in elementary or middle school, they can use stories they've previously written to submit to local competitions. They get feedback on writing and get a chance to win prizes like gift cards and tickets. It's good to encourage your kids to early on to be active in learning. Win-win situation.
This one is good: https://www.writersinknonprofit.org/writing-contest
This one is good: https://www.writersinknonprofit.org/writing-contest