I recently moved to another county. do I have to pick a doctor or is there a way to stay with my doctor of 20 years. she is not in the cal optima network

Even if your move is "permanent" you'll still have 6 months to switch unless you've figured out a way to maintain a legal presence in Orange County. If your doctor is not in the Cal Optima network & you've been seeing her for 20 years then you should be fine going forward.

Yes u would I believe especially if your doctor is not in the Network but check with your new insurance or your doctor to see what insurance they do take.