I love this question. First of all don't disregard any information any other expert has given you, all of their answers will help you. However, if you really want to grow your $500 quickly, eliminate all of your assumptions about money. I hate to break it to you but $500 is almost nothing investment-wise.

So what you're really asking is how can I make money from nothing? Realistically, getting a job (which you should do for sustainability purposes) is not a tangible way to generate a substantial amount of income at 16. Investing your money may lead to substantial amounts over a long period of time (at least 5+ years assuming your investment was well researched). If you want to create capital from nothing you need to develop a skill or realize opportunity where most people don't.

I would suggest reading this article on how entrepreneur students create large amounts of capitol on only $5.

https://www.psychologytoday.com/blog/creativityrulz/200908/the-5-challenge

So to answer your question: If you want to create money from nothing you need to begin to think like an entrepreneur and realize opportunity where others may have not.