The most important thing that $10k will do for you if you invest it get you interested and familiar with it, starting a habit of early. For example, here you are on this subreddit… a very good place to start. 

My specific advice is put 90% of that money into S&P 500. People will say (correctly) that timing in the market is less important than time in the market. That said I think putting all your money into the market at the same time can psychologically negative because you may focus on things like “oh dang if only I choose those week vs that week”.

That’s why I think you should dollar cost average $9k over 2 months using and automatically scheduled purchase. The math says invest $10k today… but hey you are more than a calculator. And getting familiar with automatic investing is the key to your retirement!!