Get to know the professor and your classmates. The better you know them, the easier it will be to overcome anxiety and shyness and to practice speaking with them in and out of class. Ask questions and volunteer answers in class. Don't miss these opportunities to practice and clear up problems. Complete all assignments on time.
Language is cumulative.
Missing an assignment is like missing a chapter in a story or a vital ingredient in a chemical formula. Study every day. The brain can only retain so much every 24 hours. A week's material cannot be learned in one weekend study session. Review part of every study period.