Today

I started italki, but I don't know what to do on this.
I want to make a new friend.

(yukatt-さん、こんにちは、友達になりましょうです^^ I hope I said that correctly.  

As for the minor corrections, remember that the word "I" is always capitalized, especially at the beginning of a sentence :)  You can also use the word "here" instead of "this," and say "I don't know what to do on here."

Also, on italki, you can continue to write notebook entries in whatever languages you want to learn and get feedback from native speakers.  You can also find language exchange partners, but I guess you already knew all this ^^ If you need help with anything, please don't hesitate to ask! Good luck!)