I study in xxmiddle school,Class 10,Grade 1.
这里漏了be动词,应该是I am study in xxmiddle school,Class 10,Grade 1.
many hobbies,many后面跟复数名词
My favourite subject is art,and I'm not good at science.
这一句在逻辑上有问题
你可以说
My favourite subject is arts,(继续拓展arts的内容)
或者说
I am doing good at art,but i am not good at science.
I hope,in the future,I can to keep my advantages,and correct errors.这里加一个逗号会好一些.
逻辑上有些不严谨.
初一的学生已经写得不错了..鼓励...