First of all, you’re supposed to pull over to the right-hand edge or curb of the highway, clear of an intersection, and stop. Some people get confused and stop in the lane of traffic, creating a very dangerous situation. Others make left turns into private driveways or businesses, still others continue on their way, thinking the sirens aren’t for them.
None of those last few examples are of course the correct thing to do, and could lead to additional violations being charged.
After you’re stopped, the Officer will make contact with you, during which time you should be advised why you are being stopped. You are required to furnish the Officer with your driver’s license 12951(a) and (section 12951(b) California Vehicle Code [CVC]) and the vehicle’s registration card, or a copy of that document. You should NEVER keep your Certificate of Title in your car. That is your proof of ownership of the vehicle. It doesn’t validate your registration, and if someone else gets hold of it, they could try and claim the car as theirs.
You could be warned for the offense(s) you committed, or issued a citation. If you are issued a citation, the Officer will explain what you’re being cited for and then ask you to sign the citation. The citation will have all of the pertinent information on it, including: the date and time of the violation, your name, the offense(s) you’re being cited for, the location of the offense(s), the Officer’s name, and applicable court dates and information. Signing the citation ISN’T AN ADMISSION OF GUILT, MERELY A PROMISE TO APPEAR. If you refuse to sign the citation, you can be arrested 40302(b) CVC and your car could be towed (22651(h)(1) CVC).