You want to create a plan for your entire life? That sounds really fucking boring, not to mention destined to fail miserably. If you think you're worried now without a plan, just think how worried you'll be when things don't go according to your plan.
If you're healthy, you have nothing to really worry about. If you're not, there's your plan until you achieve some semblance of health.
If you have all the money you could ever need, then you have nothing to worry about. If not, get busy figuring out how to make at least enough money to live on. For some, it's simply, "get a damn job." For others, you'll have to figure it out on your own.
If you're getting all the sex you want, then you have nothing to worry about. If you're not, then get busy learning the ins and outs of relationships and all that crap.
If you have some skill that you're really fucking good at already, then you have nothing to worry about. If not, you get the idea.
No one can tell you with certainty what to do with your life. Pick a thing and start doing it until it's no longer interesting. Then pick something else. Stay in touch with your family and friends. Exercise a lot and eat as healthy as possible. Make some money, have some sex, take some risks, whatever.
Good luck.