California it passed the first no-fault divorce statute in 1969. The state is a pure no-fault state, meaning that neither spouse needs to assert "cause" when filing for divorce. Instead, couples may divorce if the couple has "irreconcilable differences." There is also a decree of legal separation, which is a divorce in all respects but status- the parties remain married.
People often ask whether there is some alternative mid-way status, a "legal separation." There is not. What you want to know is that California provides that when people are separated , "the earnings and accumulations of a spouse and the minor children living with, or in the custody of, the spouse, after the date of separation of the spouses, are the separate property of the spouse."
What constitutes separation is the substance of a statute effective January 1, 2017:
(a) "Date of separation" means the date that a complete and final break in the marital relationship has occurred, as evidenced by both of the following:
(1) The spouse has expressed to the other spouse his or her intent to end the marriage.
(2) The conduct of the spouse is consistent with his or her intent to end the marriage.
(b) In determining the date of separation, the court shall take into consideration all relevant evidence.
There are useful and effective self-help divorce sources, and each county in California has a Family Court Facilitator, an attorney who helps people go forward with their divorce, not as their lawyer but providing legal advice and for no fee. However, the best resource for someone thinking that divorce may be imminent is a family law attorney- I'm one of them.