Number one, you don’t need to ask for a divorce in the state of California. If someone wants a divorce, they get it.
But if that does happen to you, I would suggest that you start collecting and copying all bank statements, copies of insurance, all statements regarding any bills due, mortgages, copy deeds: anything that you might not even think is important, copy it. If it’s not important, that’s fine, but at least you’ve got it. If you are the person that pays the bills, you’ve probably got it anyway. But you can’t take the risk that it might disappear. So copy everything, move it to someplace safe, call a divorce attorney, and make an appointment.
Let’s say you’re not sure you want the divorce: that’s fine, just get your information. It’s like preventive medicine — there’s preventive law. Just have your information so that you feel safe and comfortable.