Why I am still here

Hi, everyone!
I love to communicate and meet new people! On this site I signed up because I want to improve my English! I want to talk in English. In return, I promise an interesting pastime, and to help you learn the Russian language :)

"I promise ... teaching the Russian language" is incomplete because it does not say who is teaching the Russian language.

I think "to help you learn" best expresses what you want to say, but these are some other options that you could use:  "I promise ... to teach you the Russian language", "I promise to be ... teaching you the Russian language"