Moonbeam has a good point. Have you thought about an internship or fellowship somewhere? A lot will be unpaid but there are a ton of paid positions that will house you for a summer or even a year where you can get a ton of experience. If you have an idea of what you want to do, why don't you contact a hiring manager or someone high up and say "if I wanted to apply for this position in the future, what would be the most important things to look for?" and they should tell you which path would be most appropriate for you.

Or, since you are talking about geology with w federal service or along those lines....go to usajobs.org and check out some jobs that look interesting. They will have requirements on there and key things they look for when reviewing applications. That will also give you a good idea of what you need to be competitive.