You can seek both custody and support orders BEFORE you actually separate. The California Family Code requires parents to provide for their children's health, education and shelter. It doesn't distinguish between separated parents or parents living together.
You should meet with a Family Law attorney as soon as possible to better understand your choices. California Law also provides that if you need the services of a lawyer in order to obtain benefits for children, the court has the power to not only award child support, but to make an award that the other parent help pay for your attorney.
Typically, the process is as follows: You would file a petition to establish a parental relationship with the biological father (Paternity action) and as part of that petition you would seek 1) Custody; 2) Child Support orders including health care costs and child care expenses to allow you to work and 3) Attorney fees to obtain the orders.
In determining child support, the court would consider both parents' income as well as the amount of time the each parent is responsible for the care and custody of the child.
In determining custody, the court would take into account which parent is most fit and in whose custody the child's best interest would be. Yes, keep your journal as up to date as possible as it will help the court in making a determination of what is in the child's best interest.
Best of luck to you and your litttle one.
You can seek an order while you are still together, but the support order is likely to be deferred until you are actually separated. Part of support considerations are the costs of child care expenses, which are ordered in addition to basic child support. Those expenses, and reimbursement for one-half of uninsured medical costs are likely to be ordered while you are still living together.
The way the custody determination is made is as follows. Each of you tell the court what you expect the parenting plan to be and you are referred to a Family Court Services mediator, who tries to help the two of you work out an agreement that is in the best interests of the child. Please read the guide I wrote for Avvo on preparing for such a mediation - http://www.avvo.com/legal-guides/ugc/preparing-for-a-family-court-services-mediation-in-a-custody-dispute
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