I want to change my career but i'm 31 and don't know what to do?

The US Gov is is always looking at gaining experienced employees for all kinds of Jobs. The only ones with any age requirements are your Law Enforcement (FBI, CIA DEA ex) and even then its only for they're Agents. ysts and support staff can be any age and often have worked in separate fields before. Try www.USAJOBS.com Its the Federal Governments job site. Good luck!