hi~ joy. i am lucy who want to speak Enlish very well. ->

Correction: Hi Joy! I am Lucy who wants to speak English very well.

Correction : want -> wants

Nice to meet you!

i cant sleep tonight. because i am ready teaching my children yet. so i am preparing it.
-> Correction : I can't sleep early tonight, because I need to teach my children. I am preparing for it now.

i am headack now, and i am sleeping.....
-> Correction : I have a headache now, and feel sleepy. But, I am excited to meet you. See you soon!

Correction : Anyway, I am excited to meet you.