"MY GRANDFATHER LAST NAME WAS KISPRIDILOV IN YUGOSLIAVA."
His last name was KISHPRDILOV. Such surnames are common in Voivodina, the northern province of the republic of Serbia. Your GF couldn't have come from Yugoslavia because Yugoslavia hadn't existed prior to December 1, 1918. Since this Serbian province was part of the A-H Empire when he came to the U.S., you should check Austrian files from the area rather than Serbian ones.
MY GRANDMOTHER PARENTS NAMES WHERE STEPHEN SEKULICK AND MARY GOUGICH.
Hardly. Their last names were SEKULICH and GUGICH. Sekulick and Gougich aren't Serbian surnames.