I know that there are already a few opinions on how to use it, but here's what I'd do; invest, say, 75-90% of your fiat into bitcoin. There's a high likelihood of you making profit in the next couple months or years, if you're willing to wait. Then, convert the rest into altcoins; I'd say ETH is looking good, yep. It's had a huge increase since the last time I've purchased, which was a while ago.

Good luck and have fun making some moola.