I mean, that is a completely ahistorical and contrived scenario - "everyone" meaning the entire working class or including the bourgeoisie? And because reality is created through the course of events and struggle, my projections with regards to specifics would be meaningless. Further, there are many hypothesized forms of organization with regards to your questions on who makes decisions and how resources are distributed. Essentially, those are things that have to be decided by the working class itself in the course of experience and people's preferences.
Not to mention, socialism has to be a global development -- but, if it started in the U.S., that would rock the very foundations of capitalism as the U.S. is the capital of capital (
)... the repercussions in the rest of the world after something like that are unpredictable. It would be an amazing inspiration to and opportunity for the working classes in other countries.