What is the penalty for 1st offense possession with intent to sell 1 oz of cocaine?

Instead of worrying about the penalty, you need to focus your attention on how you can avoid being convicted. Time to shop for a lawyer.

Possession of cocaine for sale is a violation of California Health and Safety Code Section 11351. The penalty if convicted of this as a felony is 2 years, 3 years, or 4 years. Yours truly

That is an extremely serious charge. That is a felony with a maximum sentence of up to 20 years in prison. More than likely you are at least facing some jail time and possibly even prison, even for a first offense. Given the small amount a lawyer may be able to negotiate it down to simple possession which is a much less serious offense and would also make you eligible for 7411 which would keep the matter off your public record as well as prevent any driver's license sanctions. You definitely need an experienced criminal attorney on your side. There may be issues with the arrest, search, seizure, etc. that could be used as leverage to reduce the charges or get the matter dismissed.

Up to 20years in prison. At least in Michigan.