I am a member of a sorority that continues after college. I think it is important first to consider the type of sorority you are interested in and conduct your research. Sororities can be different individually; this includes requirements and processes. The common Fraternity & Sorority Councils are:
Multicultural Greek Council
National Pan-Hellenic Council
They are all unique in their own ways.
I would recommend that you ask your student life office about the various sororities on campus and obtain brochures and websites for the ones onsite. I also suggest researching and attending any events of sororities on your campus so you can learn more about what they do.
Make sure you keep up your grades, be active on campus and help with the communnity.
I was in a sorority in college, and I found it to be one of the most rewarding experiences. I met many friends who I am still close with 15 years later! I would recommend that you ask your college what sororities there are and how to become a member of one. Sororities are usually focused on ensuring members get good grades and are open and social people. I'd encourage you to keep up your focus on studying in school and when it comes time to join a sorority, be open and honest and your true self.
Best of luck to you!