Question on Link Point API (First Data)

Hi

For anyone using Link Point API (First Data), I am having trouble setting it up. Info that the shopping cart ask are, Store number: I know, Secure host & port: I know, Certificate filename: I don't know. What can It be. The only thing that was given to me was this Digital Certificate that have a bunch of numbers and letters. Also it ask Order prefix: I have no idea. Any help would be helpful

Thank

David