Hi~~*

I came went to school today..
나는 오늘도 학교에 왔더

10:00am to 7:00pm there are lessonsT-T
오전 10시부터 오후 7시까지 수업이 있다ㅜㅡㅜ

There are lessons from 10:00am to 7:00pm.

If you are interested in Korean send me a message.
만약 한국어에 관심이 있다면 내게 메세지를 보내줘

I want to help.  :p
나는 도와주고 싶어

I have an lot of interested in English, and Chinese.
나는 영어, 중국어에 관심이 많아서

You could also say, "I am very interested in English and Chinese." 

I need to help.>o<
도움이 필요해

좋아요, 정 씨!  All of your sentences were easily understandable, and only needed minor corrections.  Great job!