I'm new in to this. Or you can say: I am new in here.

Hi! I'm new in italki. I don't know so good much about how it works! I want to enhance my english. My main native language is Spanish. I want to talk with people who wants to learn is learning spanish, to help us to each other. so we can learn from each other.

Or you can also say : I want to talk to other people who wants to learn Spanish. That way we can learn and help each other.

Other than that, your English needs a bit of polishing but you are doing well :)

I'm new in this.

Hi! I'm new in italki. I don't know so good how it works! I want to enhance my English. My main language is Spanish. I want to talk with people who is learning spanish, to help each other.