I'm 20, currently on Christmas break during my sophomore year at a popular engineering school in Alabama. I think I can relate to your experience(s), so please allow me to share my opinion:

I moved out of the house at 18 to attend college. I only went to the school that I go to today due to a miscalculation, believing I could afford it. I took out a loan to afford Freshman year. All is well. I actually took out too much in loans. I had some extra money, so I decided to try out the stock market. I invested in energy in October 2014. Bad decision. Lost ~50% of my investments.

With that being said, I went into it knowing it was a learning lesson. Here's the deal: investing is long term and for the "wealthy." With your current financial situation, you need to invest in yourself. If you can't afford to lose all the money that you plan to invest, then you are not ready to invest that money. Instead, save it and use it to pay for self-investing or important things like a house. Go to the military, trade school, or college if one of these is appropriate for you.

NOTE: This information does not apply to 401k/IRA savings. Put as much as you can possibly afford into retirement. Every dollar you put in today will look really good whenever you're 60/70/80. People who save all their life will not be able to catch up to you if you put in just a few hundred/thousand dollars in an IRA at such a young age. Compounding interest/dividends over many years is powerful.

If you know FOR A FACT that you won't need the money for X amount of years, then put it in a high-interest savings account or a CD for X years. Once the money is gone, it's gone. It's better to have made it develop yourself rather than go into the pockets of smarter stock investors.

tldr; Put it in a savings account and invest in yourself to increase your income potential.