Every district requires you to do a separate digital fingerprinting session called LiveScan. LiveScan allows the district to:
Do a criminal background check
Subscribes to alerts in case you get arrested while you are hired.
Even if you have a LiveScan result for one district, you'll need to do it again to apply for a different district.
Do a Google Maps search for "LiveScan" to see places near you. They are all over the place (notary and shipping stores sometimes have a LiveScan machine). An option for CSUN students is the CSUN Police Department, which is by appointment only -- call 818-677-2113 to set up your appointment.
A specific form that the district will provide you.
Valid California ID (i.e., driver's license or other ID) to your LiveScan session. If you don't have a California ID, an out-of-state driver's license will also work. If you don't have that, you select combinations of other documents to prove that your identity.
It can be helpful to apply lotion to your hands before the session if you have dry skin.