This is very good.  Almost no corrections are needed.

Correct my words please:)

Hello. I'm a native Russian speaker. On this site, I want to learn to speak English and understand spoken English. In exchange, I can help you improve your Russian language skills and talk to you on a variety of topics, about different things, on Skype. I also speak the Tatar language, if you've heard of it.

Correct my words please:)

Hello. I'm a native Russian speaker . On this site I want to learn how to speak English and understand spoken English. In exchange, I can help you to improve your Russian language skills and talk to you on a variety of topics, about different things on Skype. I also speak the Tatar language if you've heard about this.