I need some advice!! undergrad looking for masters program!

I am currently a third year student at UC Davis. i will be graduating with a biological sciences degree, however i now realize that i should have gone into nursing right after high school ive been reading a lot of threads and researching my options. i want a program like the one at UCSF (MEPN) for students with a B.S. in a field other than nursing who want a masters in nursing. i would love to attend UCSf but i feel that my chances of getting in are low because i dont have much experience and my gpa is a low 3.3... i have yet to take my GRE, but does anyone know some averages for GPA, GRE, and experience required. im really confused right now because i feel that the time is coming for me to apply to schools yet i also feel that i might be wasting my time because i won't get accepted... any advice will be helpful!!!