If you speak Russian at home, you might be interested in taking a course on Russian for heritage speakers. I offer a one-credit course for heritage speakers, RUS 491, every fall semester. In this course we learn word endings and verb conjugations and a lot of cultural information, but not the way it is done in traditional Russian classrooms, but leveraging the linguistic intuition you have developed from years of hearing and speaking (but often not reading and writing) Russian.

If you want to start learning about the structure of Russian on your own, I highly recommend looking at these materials, which colleagues of mine and I have created for students like you: http://digitalrussian.middcreate.net/heritage/