I’m going to admit: this is slightly embarrassing, but you have to start somewhere. For a long time, the only books I could claim to have stories published in came out when I was in high school.
Don’t get me wrong: at 15, finding out my assassin-droid short story “My Function is to Kill” was going to be published in Creative Minds ’88 made my year. The anthology of student writing was published annually by the school division my high school was in, and it was a real cross-section of what a lot of us were going through and how that came out in our writing. (Er, well, I don’t know what an assassin droid says about my high-school experience, but I thought it was cool.)