CA is the nanny State. I was born here so I can say that
When I was a kid 49 cc scooters required nothing. That was the whole point.....
I checked current California law/regulations and CA now treats 49cc scooters like a motorcycle...
1) You have to have a valid CA drivers license
2) you have to get a motorcycle endorsement
3) you have to register it every year......
4) you have to wear a motorcycle helmet
The only difference is that you DO NOT have to carry liability insurance if it's 49cc.