If you are interested in the graduate (M.S. and Ph.D) programs in Physics, follow this link for information. You can also get to that page by following first the "Graduate" link under "Programs" on the navigation bar, and then the "Applying" link you will see near the top of the page you reach.
If you are interested in an undergraduate degree program at CSU you need to apply though the university's office of Admissions. If you are outside of the US (and are not a US citizen or permanent resident) you might also want to get in touch with the university's International Programs office. Physics majors are eligible for several prize scholarships and some part-time jobs may be available in the department. A detailed description of the physics major curriculum is available here.