Iver Olsen Slettum

Hello...you have helped me on many occasions so now I am helping a friend to find out about his family. The name is Iver Olsen (https://www.findagrave.com/memorial/39440168/iver-olson) and Kari Nelson Olson (https://www.findagrave.com/memorial/39440199/kari-olson). I found the basic info on findagrave.com and then looked on ancestry. Found a few people that had this family. Also, found them on the 1865 census in Norway. https://www.digitalarkivet.no/en/census/person/pf01037080001844 My questions now: 1. Can Iver's parents be found in the 1865 census from Norway. I tried but couldn't figure anything out. 2. I think they left for America around 1905 or so, maybe a few years before that. Where should I start to look for passenger lists for them? Thank you for any help.