The next step would be to visit your professor or your TA during their office hours.
If you have tried all of the above, then either seeing a different professor or talking to peers may be the link to understanding the material. In this case, take a look at the HKN website. Tell them what you have done already to try to understand the material, and what you would like (a different professor or peer help).
Tutoring centers that are available:
|Physics and Chemistry||Science Learning Center(SES)|
|Mathematics||Math Learning Center(SEO 4th Floor)|
|Computer Science||See Professor Reed (SEO 9th floor) or ACM (SEL)|