Re: What next?
Have you explored the resources available here on the DOS website? If you go to http://careers.state.gov/officer, there is information about what the State Department seeks in Foreign Service Officers, the career tracks, a tool to help you determine which one would be best for you, and information about the multi-step selection process that begins with registering for and taking a written test, etc. There are also links to Diplomats in Residence, who can answer questions. (They are all in the US, but you can send email to them.) Good luck!