Svendsen

Hi There, I am researching the family history of my partner and have hit a bit of roadblock and I havent gone all that far back. I am looking for records on Frederik Svendsen born I believe around 1890 or so he married Emilie Olsen also believe to be born in the 1890's they had at least 2 children, both boys, one was Gunnar Svendsen born 2 Feb 1914 who came to Australia 2/3/1940 on the ship MS Brand broke his foot and stayed here in Australia. I am unsure of the 2nd childs name but I believe that they were all born in Oslo, not sure of the parish though. Can anyone help me with any information or any tips on finding this information? I am relatively new at this and dont really know how to proceed. ETA: Not sure if this helps but my partner apparently still has relatives in Norway, it is believed that one of his cousins owns a hotel/pub. Thanks Flip