Talk to your instructors. Make use of their office hours. If you are having difficulties in class, or there is some missed communication, your instructor is the best person to help you. You're in charge of your own education. Attend all classes all the time.
Prepared students are the norm in college.
Do all the reading assignments prior to class. Take reading notes outlining the major points and jot down questions or comments. Even though some faculty may not follow the text in class, all expect you to know what the text contains. Concentrate on the classroom activities during class time. Focus your attention and be aware of the speaker's emotion, body language, and key words.