Fortunately the birth certificate is a permanent record, kept by the county. All you have to do is go to the records office and prove who you are (SS card, Driver's License, etc. ) and they will re-issue your birth certificate.
Births are recorded in the County Clerk office, and also reported to the State's Vital Records Office. Certified copies are available from either source, usually for a fee.
If you have lost your birth certificate you will need to contact the clerk of the courts in the county you were born in. They should be able to provide you with the steps to replace yours.
Consult the Department of Health in the locality where you were born. They keep records of all births and will provide you a new birth certificate for a fee.
