Hello,my classmates,
Like many students,I have many hobbies.
That's all.Thank you !

One possible version: Hello, my classmates, Like many students, I have many hobbies. I like sports. I also like music. Sports are good for my health. I often take part in all kinds of sports. I go running in the morning. I sometimes play basketball or ping-pong with my friends after school. Doing sports helps me keep healthy. Music can make people happy. My mother is good at singing and my father does well in playing the piano. Under their influence, I have become interested in music. I like singing and playing the piano. My dream is to become a singer or a pianist. That's all. Thank you!