Hello, everyone! My name is [Your Name]. I am very happy to have the opportunity to introduce myself here today.

I am a 12-year-old boy/girl from [Your School Name]. I love learning new things and enjoy spending time with my friends. My favorite subject in school is English because it allows me to communicate with people from all over the world. I also like reading books and watching movies, which help me improve my language skills.

In my free time, I like playing basketball and riding my bike. These activities not only keep me healthy but also teach me the importance of teamwork and perseverance. I believe that staying active is an essential part of life.

I hope to make more friends and learn more during my time at this school. Thank you for listening to my introduction.

大家好！我的名字是[你的名字]。我很高兴今天有机会在这里向大家介绍自己。

我是一名来自[你的学校名称]的12岁男孩/女孩。我喜欢学习新事物，并且喜欢和朋友们一起度过时光。在学校里，我最喜欢的科目是英语，因为它让我能够与世界各地的人交流。我也喜欢读书和看电影，这些都能帮助我提高语言能力。

在空闲时间，我喜欢打篮球和骑自行车。这些活动不仅让我保持健康，还教会了我团队合作和坚持不懈的重要性。我相信保持活力是生活的重要组成部分。

我希望在这里交到更多的朋友并学到更多东西。谢谢大家聆听我的介绍。

这段自我介绍简洁明了，既展示了个人的兴趣爱好，又表达了对未来学习生活的期待，适合用于小学升初中的场合。同时，中英文对照的形式便于理解和记忆，非常适合需要双语表达的学生使用。