All silly conspiracy stories aside, Groom Lake is where the US Department of Defense conducts tests of secret aircraft technologies. For example, they were instrumental in the "Have Blue" testing program that later became the F-117 Nighthawk stealth fighter aircraft.
Usually such places are only open to those with US security clearances. Such clearances are only rarely issued to foreign nationals. Citizenship in the US is usually a requirement.
Having been at the Naval Research Lab as a student intern decades ago, I can tell you that the US Military is very serious about keeping secret things secret. Frankly, I detested the security clearance bureaucracy so much that I went to work somewhere else. There is no glamour working in such places because you can't discuss it with anyone outside of your immediate work hierarchy --not even your spouse. Going to a bar with friends or a cocktail party, you can't say anything about what you do on the job --not even incidental irrelevant stuff to the projects you work on.
So what happens at Groom Lake pretty much has to stay at Groom Lake. Were I in your your shoes, I might seek work with a large aerospace firm such as Arianespace. You'll get all of the thrill, and there is even a fighting chance that you can brag a little about how, yes, you really are a rocket scientist.