you don't get a class selection for finishing survival, did one of your friends give you one, or you completed the "station tools" quest (2 parts), that rewards a selection.
aside from that, you scrap schematics into knowledge points and combine at the research desk.
farmer is more difficult to *start* with, because of the combat challenge, as it's a support class.
if you're working together in a group, things will be muuuch easier than if you were solo.
- - - Updated - - -
along with what saku said, if you place a "static" trader, it should stay.
nothing we can do about trader despawns, is a vanilla issue.
glad everyone is enjoying!
- - - Updated - - -
it's been a few pages, so if anyone has a discord and would like to join ours, there are a lot of people around for help and general chatter