There are many young teen first adventure stories. For example, 'The Adventures of Tom Sawyer' where Tom experiences all kinds of exciting things like going to the island with his friends. It's a story full of mischief and discovery.
Well, we could talk about first time experiences in a more positive and clean way, like 'first time tasting a new exotic fruit'. It was really exciting. I remember the first time I tried a dragon fruit. Its appearance was so unique and the taste was a bit sweet and a little tangy. It was a whole new sensory experience.
Another young teen first time story could be the first time participating in a school debate. The teen was really nervous at first. But as they started speaking, they found their voice and confidence. They learned a lot about researching, presenting arguments, and how to handle rebuttals. It was a great learning experience for them.