Don’t waste time chasing grades. It’s pointless: nobody will ever look at your transcript :)
Learn English, but on your own, not in a course. A course will teach you conversational English, and without practice you’ll forget it instantly. Learning English is easy! Read and watch in English whatever you’d find interesting in Russian.
Be critical of what you hear in lectures and seminars. Most of the time the people giving them are just biological devices for retelling a textbook.
Read practical books on the subjects that interest you.
If you can’t skip classes (attendance is often the only thing you get credit for, though there are ways around that too), read right there in class.
Don’t sign up for the military department, the university’s reserve-officer course that keeps you out of the draft. For one thing, it’s cheaper to get out of the draft some other way. For another, you’ll save time and nerves.
Remember: wits and creativity easily make up for knowing the course manual.
University helps you grow as a person, not as a professional. Learn discipline, learn to work in a group, talk to people and make as many contacts as you can. They’ll give your career a good start. Jobs and business ideas most often come through people you know.