There is no law concerning dating at any age. There are laws prohibiting sexual acts with a person under the age of consent (age 16). So it is illegal to perform sex acts with you prior to your 16th birthday, regardless of how old he may be.

Is it legal to date a 18 when your 17?

California – The age of consent in California is 18. It is illegal for anyone to engage in sexual intercourse with a minor (someone under the age of 18), unless they are that persons spouse. California employs a tiered system where the greater the difference in age, the greater the penalty.