Goldberger family

Hi everyone,
My name is Alex Goldberger and I start the family tree, on all of the sites on the internet appear a lot of Goldberger , lot of my family are no longer alive the same the information ....
The question is : if i do not have documents , pictures or acknowledgment of the family how can you be sure which of these Goldberger are part of my Goldberger family . What I do know from my father is that origin of my family is in Spain ( verbal information ) . From there they spread thru all Europe . Maybe you can give me some help please how to find the real Goldberger , ho is connected with my Goldberger family. Thank you for your help ( my email address is life542007@yahoo.ca ) with respect
Alex