How can I acccess my personal health record?

Ask. Every state has different laws. However, in most states you own your records. Ask you physicians for copies if you want to know what is in them.
Ask your doctor. Usually your doctor provides information about the process of this in his/her practice, when you become a patient. In general, you can receive a copy of your record by requesting it in writing. Depending on the type of doctor and the problems you've been experiencing/treated for, your doctor may want to go over this with you in person. S/he decides about this by considering your best interests.
Could be complex. Depending upon your reasons and the character of your records, could be challenging beyond 7 yrs, as most records are destroyed beyond that point. Records of mental health issues and treatment outside Calif might be tough to access. Contact the Board of Medical Examiners in Sacramento, and they should provide guidance in how to obtain existing records.