You can apply for a student credit card since you are currently a student. After graduation, you can keep using your student card. If you want a cash back credit card, you should consider the Discover it® for Students card. The card offers 1% cash back on all purchases. You can even get 5% cash back if you enroll in rotating categories every quarter. Also, shopping via Discover Deals will bring you from 5% to 20% cash back.
If you are planning to apply for a credit card after your graduation, you should consider credit cards for people without credit history.