Need Help With Constructing A Marketplace Website

I'm still very new to rails, but I want to start working on my project.
I want to create a website that is similar to 99designs where people can
connect and perform jobs for each other.

I'm thinking about what would be the best way to map it out. Would I
need a separate controller/model for the freelancer vs the person
hiring? They will all be associated with the user controller correct?

Then I would need a profile, would this be considered a user has_one
profile or user has_many?

Thanks! Any additional advice would be great.