My team was wondering if we qualify for state in Northern California or Southern California, will we be qualified for the other?
Say, we win a competition that qualifies for state in Northern California, will we be qualified for state tournament in Southern California?
Does it matter since Norcal and Socal are part of the same state?
My state isn’t divided into two parts, but I’m pretty sure that you likely qualify for both. I wouldn’t take my information to heart though. A better person to get information for would be someone qualified for state from your region.
Just helping 
You qualify for CA State Championship. With the quaification in hand, you can register either to NorCal or the SoCal event. You can pick, but you can go only to one and can’t change your mind after you select and register.
They could just split the state in half, but they usually leave it up to the teams as to which event would be best for the team. Historically, one event could be more competitive than the other, so if it’s a matter of a couple extra hours of driving it may be worth it.