How do I get around when I cannot drive anymore?

Try this page from the Peninsula Agency on Aging

https://paainc.org/transportation-services.html

You mention your husband is a vet so maybe start by calling the VA to see if you qualify for any driving services?

If you have means, a private service like Visiting Angels can provide a companion (which is the least expensive level of caregiver) who can drive you anywhere. I don't think there's any minimum of hours required but the best people want consistent hours. My aunties in FL have a companion come M-Sat for 4 hours every morning. It works great for them.

If your means are limited, call your county and have them come in and assess you for free or very discounted driving (and other) services. In MN my in-laws qualified for housekeeping and food prep services. Not sure what your county provides.

If you need help downsizing, this is another issue. If you are serious about it then I would let your CA children know and discuss a plan. All expenses for them to help you should be covered by you. If they have jobs it means they may have to use up their limited vacation days or take leave of absence. This is their reality. I think in CA they may have a law about family care leave. Your children will tell you.

May I humbly suggest that you consider downsizing and getting yourselves into a nice senior community while you are both still able to make your own decisions and it isn't too taxing physically? It will only get worse as time goes on. Why wait for a crisis and the then have to make changes and decisions under duress? I understand that aging often feels like just having your layers peeled away one (or more) at a time. Moving is strenuous and difficult and doesn't get any easier. Perhaps you may consider moving close to your children? At least you'd get to see them (and grandchildren). Just a thought. Wishing you lots of help!

You do not tell us too much here, and I am not one to go to profiles overmuch to research. I cannot know where you live. My bro recently found out by demolishing his car and himself, that it is time to stop driving. 85 with balance issues, brain tumor diagnosed after accident is benign and there for decades likely, but pressing on his balance centers. Also a probably or possible early Lewy's by symptoms. So no more driving. He lives in Palm Springs which means not good transit and too hot to wait for the buses so he is down to Uber and Lyft, which don't work with no computer or cell phone--neither of which he has. Nor the wish to learn them now. So he has found one driver. And he has entered assisted living where the bus takes him to his appointments, and goes on field trips, to shopping malls, and etc. once a week.
There are many options, but if you are alone where there is no transit, no computer or cell to summon Uber of lyft, no funds to enter care, it is truly a dilemma. Can you tell us more about your own situation?