It's a nice day today

Yesterday I was began doing working with students work. I unknown helped a girl to prepare for the her exam. Today she very thanked me.
Unfortunately, I think that my English is really so bad :( I am going to study English and achieve an advanced level Advance :) I hope I can do it.

Valiant effort, but for the most part your sentences were somewhat hard to understand. I suggest you hit the books and study up on your grammar!