I have a 2.5 and im a sophmore and want to go to UCSD, how will i get accepted? Please answer.?

Okay so I am a sophmore and I go to chaminade highschool. Freshman year i completely messed up and got a 1.2 or something GPA. I did really bad I didn't even try. Second semester of Freshman year i got a 2.3 I think. Sophmore year first semester I got a 2.5 (1 A, 2 Bs, 4 Cs) and I am going to try to get at least a 3.3 or 3.5 for second semester Sophmore year. I go to a private college prep highschool. I really want to get into UCSD or any university in san diego, peperdine, uc irvine, and schools like that. what do i need to do...please help.