Although you need certain skills and aptitudes to join the Foreign Service, you don’t need to know everything! For example, the State Department teaches languages and also provides courses to officers before going out to their duty assignments.
The ‘college’ for Foreign Service Officers is the FSI, the Foreign Service Institute. As you advance in your Foreign Service career, management and other courses are available as well. However, if you have ambitions to earn a master’s or doctorate, Foreign Service Officers suggest that you do that before joining the service as once you are in, taking a break to pursue academic studies may not be possible.