Hi Sawyer, overall it's quite good. Don't be put off by all the corrections. There are some mistakes, but despite that, it's still quite natural.

Today is my first day in ON italki, Sso i think it is suppose I AM SUPPOSED to write something to commemorate MARK THAT (commemorate just seems to be a bit too official for what you're writing but it's not wrong).

As a college student in China, I must admit that my English is getting poorer and poorer WORSE (again not wrong but not natural) since we had ended our English lessonS one year ago. Many words have gone out of my mind because I didn't spare much time on it. I HAVE FORGOTTEN MANY WORDS BECAUSE I HAVEN'T SPENT MUCH TIME USING/STUDYING ENGLISH.

When I had the English test named "CET6", I even don't know how to begin with the composition. Thanks for TO my sister,I found italki to learn English now. I come CAME here because I want to make friends with people like you who wanted to learn languageS together. No matter where you are and which language you are speaking SPEAK. I think we can be friends by helping each other. At last, LAST OF ALL, I hope everybody have HAS a good time when learning languages!