In order to become successful at CC, use ratemyprofessor.com a lot. You’ll want to avoid professors that are literally an automated response system. This is a weird tip, but hey, people do use it.
Here is a post that I’ve made about transferring to UC Berkeley:
http://talk.collegeconfidential.com/uc-transfers/2029576-cal-transfer-student-here-ama.html#latest
If you are heading to CC, go to your destined CC right now and take placement exam if they require it. Knock those pre-reqs out by enrolling in this summer. Stuffs like Algebra or Trig. I had to work all the way from Algebra lolol
If you are sharp on Trig from High school and if your CC lets you skip over Trig/Pre-calc then:
This summer, I highly recommend that you take a “boot camp” physics course !!
It’s usually in the form of “introductory physics” or “fundamentals of physics”
This course will become a stepping stone to the Physics with Calculus or Physics for Engineers - which will transfer to UC Berkeley for sure. UC Berkeley and UCLA only accepts Physics with Calculus or Physics for Engineers.
If you want to be an engineer, you have to be VERY strong at Physics. Because I honestly think that Physics was way harder than Calculus or any chemistry courses I’ve taken.
Physics will teach you the ways of how to approach problems. So not only getting an A is essential, but Physics will give you an edge to become successful in other courses… i.e. study habits, how to solve questions, etc. This is why I want you to head-butt Physics first. Do you see my point? 
For an EC, just work or do some volunteering at a local place. Perhaps try to find a CS related since that might interest you? I did volunteering that interest me, not usually what is impressive.