I will introduce myself and I hope to get your help!!  My name is Wang Yuyan, I am a middle school student. In my school, I have met many lovely classmates and I really love them. But I'll leave them next year because I must go to high school to study more. For this reason，I’m so sad.

It's good! But remember that with punctuation (like . and , and : and ;) you put it after one word with no space, then add a space, then the next word.

For examle: I have a cat, his name is Snowball. I also have a dog, his name is Frank.