how do you search for a missing family member?

I am missing a brother and a sister, whom i've never met. I want them to know i exsist! I am trying despertly hard to find them, but im runnin gout of options. If anyone has any advice, it would be very kind and i would always thank you. Thanks for your time.

Your parents should have copies of the adoption papers/amended birth certificate, which would tell you where you were adopted from (agency, state, etc). Then I would contact that agency/state and see what they can tell you. There is a number on your amended birth certificate which correlates to a number on your original birth certificate. You will probably have to fill out paperwork stating why you are wanting this information and then hope that your birth family has filled out the same paperwork saying it is ok. If the birth family has made contact with the agency saying that he is wanting to be found, then the agency will make contact with you