I can't believe establishing Legal Parentage Before Birth is even legal

My wife and I are working with a gestational surrogate in California. We have an agency handling the medical side, but we need to understand the legal process for establishing parentage.

Questions: (1) When do we need the legal agreement done? (2) How do we get our names on the birth certificate? (3) Does the surrogate have any parental rights?

Update: Hired a surrogacy attorney in LA. Agreement being drafted now. Pre-birth order is routine in CA. Total legal budget is $10K for both attorneys.