The most important thing is to try things out. You think you might like something, then give it a shot. After a while you should know if it's for you or not.

Do be careful with the Navy though, military gigs are a commitment. Not exactly something you can just quit when you don't want to do it anymore.

If you don't know what to try, then I'd say go to college. Find a community college nearby. It can be very affordable. And the point in that is not to say you're gonna start working on a degree and then to get a job right out of college, but it's just to try things out. Take the General Education degree, if you finish it, great, but you don't have to, and don't worry if you don't. Take classes that you think might be interesting. GE classes are a great way to find something you're interested in. From there, you'll probably know what you wanna do.

So if you're really doing nothing and just work at a dead end job or something, I'd say go do some college just to help you get a better chance at finding where you fit in. Figuring out what you want to do, you can't just force it, you have to let it come to you. Don't rush it, don't panic. Be patient and don't worry about it. You'll know when it comes. Hope this helps.