It's pretty hard to find singular venture capital investors, it's much easier to find firms that work with a lot of companies, but there are some ways to do so.

Use Angellist to find singular investors, there is a dedicated section just for companies and investments. Other ways would be running similar to ICO campaigns, where you'd advertise that you are looking for investments.

Other than that, look at investment firms (most of these are quite strict, so be prepared to go through months of waiting and information).

As well as that, look to family and friends for investments, and good luck with whatever venture you are doing.