There are two motorcycle license classes in California, M1 and M2. M1 is a wider license that allows you to drive anything with two wheels. M2 is for mopeds and scooters only. Getting M1 is non-trivial, the hardest part is the skill test where you have to perform a number of tight low-speed turns. I’ve never heard of anyone doing that test with a scooter. It may be illegal. (Motorcycles are manually shifted, scooters are automatic, you may need to demonstrate your ability to operate a real motorcycle to get the license) One way around is to enroll in a Motorcycle Safety Foundation training course, it’s like $200 for two days of classes (evenings) and two days of practice (9 to 1 on a weekend), motorcycles are provided, and finishing the course waives the skill test requirement. And when you’re done, you can go and buy yourself a sport bike that goes from 0 to 60 in 2.8 seconds.
Since you only want to ride a scooter, you may shoot for M2 license. Some kind of skill test will still be required but it should be easier.
When you pass the written test, they give you a permit that you can use to buy a bike or a scooter and practice on public roads. The permit does not allow you to ride at night or on freeways.
I have a 14 mile commute from western Rancho Bernardo to El Camino in CV and I can take all backroads so a cheap scooter/ motorcycle seems like a good investment over the family truckster.
If I had to commute on a bike, I’d rather take 14 miles of light traffic on the freeway over 14 miles of traffic lights and stop signs. If you’re a responsible rider, the most likely places to get into an accident are intersections (for example, if someone turns in front of you). Cruising 65 mph on the freeway is relatively safe, as long as you keep distance and stay out of other vehicles’ blind spots.