That isn't that much too start off with; but, you could go into real-estate, and buy up Foreclosures or Bank REO's, Buy low, invest just enough, then sell high.
You may try the US Stock Exchange; but, I would not recommend it between now and October of 2020.
Another avenue is Logistics; as, things always need too be picked up and delivered.
There is also Solar Power, sales and installation is booming.
what ever venture you think may be lucrative, be careful, because, the more money that you have, the more people there will be too try and take it away form you.
Added thought: Come to Los Angeles and open a bunch of 'cannabis stores', and you may see that Billion a lot sooner.
First hand experience