First step. Read these. The advice in here is expansive and awesome:

edit: here's a post list w/ a few more.

Step 2: Never take a single word of advice. Take it all in. Let it simmer and stew and marinate in that brain / heart of yours and make decisions based on what you think and feel. Your decisions will be influenced by the mountains of advice but the decisions will be yours and yours alone.

Step 3: Don't make any big decisions you don't have to. Make little ones and enjoy the journey. I planned on working in television (like I did in high school) instead of going to college. I figured I would figure it out. I hated school and spent more time trying to figure out how to not go to school and keep my valedictorian status than actually going to school. Then I got into NYU Film unexpectedly. Then I dropped out of NYU film two years in because I lost my passion. Then I worked nights editing shitty movies and TV shows for next to nothing (maybe like $50/night). Then I took off to Australia for three months with some Aussies I had met at a bar while doing cocaine one night (no joke). Then I got back home, moved in with my parents, and accepted a job at $13.25/hr editing product videos. Then I taught myself web development. Then I quit my job and started my own business creating websites for people. And here I am. I just turned 25. If you had asked me where I would be at 25 when I was 16, I would have said, "Doing cocaine and producing indie films and living a rockstar lifestyle." I don't produce films (although I occasionally get a corporate video bullshit gig) and I don't do cocaine anymore. I also make websites. WTF? How did that happen?

Life changes and it changes fast. The best thing you can do is roll with the punches and make sure whatever you are doing, you are passionate about. You are never too old or too young to do something big or change the direction you are headed. There is a big difference in being non-committal and giving up, and changing directions though.

I was 100% passionate about film until I wasn't. I tried really hard to find that passion again and spent a lot of time thinking there was something terribly wrong with me and that I had some lack-of-motivation disease (there's a motivation/passion enzyme in your thyroid right?) It turns out I was just over it. I sobbed to my parents for literally an hour straight, sitting on a grimmy NYC curb, before the words, "I want to drop out of college" left my lips. Then I sobbed and tried to catch my breath for another 4 hours or so.

If you don't have passion for something right now, do what you like best and explore the surrounding areas. Eventually you will find something. You are young as shit. I have friends pushing 30 who are still running away to foreign lands and snorting coke and haven't even tried to figure out what they want to do with their life / what their passion is.

Learn as much as you can now though. Real life is not conducive to picking up new skills, FYI. Go learn to solder or some shit. I don't know. I wish I had the time to learn that right now.