Advice?

I haven't seen my dog for 10 years since my parents gave her away when I was a child. I miss her and I love her everyday. Iam thinking of looking to find her and find out If she is okay and see her again if she lives she is 12 now. There's a chance I know where she could be or the place that I could get some information (the place they gave her away outside their door to live with them and hopefully be happy with them) ( I know my parents were through hard times .I want to forgive and love them) (except posts etc) but how could I go to that place ? What could I say after all those years? Iam strong to do it but I want people there to trust me .(and maybe they are the people she lives with)