You've gotta chose a theme. Make a town, medival, modern, punk apocalypse, something to leave a good image in players' minds. Make it in the from of a city, as his works for all of the above themes. Good luck, I'd love to see what you come up with!
I would start focusing on jobs, as that is what would be most important to me. You'll enjoy doing all the PMC stuff a lot more knowing you have financial backing and don't have to rely on others. Again, just my opinion.