1. At school, I enjoy chatting with my close friends.

2. At school, I enjoy cleaning with other classmates.

3. At school, I enjoy playing soccer in the playground.

4. At school, I enjoy eating cookies at the school shop.

5. At school, I enjoy playing basketball in the gym.

6. At school, I enjoy singing in the music room.

7.At school, I enjoy using the computer in the computer room.

8. At school, I enjoy talking with my partner in class.

9. At school, I enjoy flying paper planes out of windows.

10. At school, I enjoy getting praise stickers by doing good.

(Would you check the sentences, please?)

Everything is fine except for one word. I'd change "in" to "on" in #3.

The sentences provided seem grammatically correct. However, I would like to point out that while some of the activities mentioned are common at school, such as chatting with friends, playing soccer, eating in the school shop, or using computers in the computer room, others might be against school rules, like flying paper planes out of windows. It's important to make sure that the activities we enjoy doing at school are safe and allowed by the school's regulations.