Funding is important for entrepreneurs. Of course, you may start with your money, which is quite common. But sometimes Crowd-funding is one of choices.
The following websites are crowd-funding agents.
However, there are many risks for crowd-funding.
First, your idea might be stolen by third parties. Second, crowd-fund is raising funds from normal people. If project owners fail to reach the objectives, it might be difficult to find other places to raise funds due to damaging your reputation by such failure.
In this sense, crowd-funding is too risky to use for the start-up. Rather it might be better to use for promotional purpose.