To get your passport you need to have an "Original Birth Certificate". It does not cost that much; you can apply for one at your County's office of vital statistics Birth, Marriage and Death. Each County however have a different office that handles that so, you need to check with the County where you were born.
To get your passport, you will need your birth certificate. The copy will need to have the raised seal and be signed by the person in charge. Check and make sure, you have the correct copy, before you apply for your passport.