This is really good for writing without a translator. You know more English than I know Portuguese, so good job.

This is how your post would read if it was written by a native English speaker (I should note that the grammar isn't perfect, but in informal chat it often isn't):

Hello guys, I'm here to find someone to talk with. I'm from Brazil, and I'm learning English. As you can see, I don't speak english very well, and my pronunciation is terrible. If someone can add me on Skype to talk with me and help me to improve my english skills, I would like it so much, and I'll be very grateful.

With essentially perfect grammar, but more for writing:

Hello guys, I'm here to find someone with whom I can talk. I'm from Brazil, and I'm learning English. As you can see, I don't speak english very well, and my pronunciation is terrible. If someone can add me on Skype to talk with me and help me to improve my english skills, I would like it so much, and I'll be very grateful.