Where do student entrepreneurs get money?

Most universities run incubator programs. You'll get free office space, legal services, financial, and similar stuff.

That said, if you're doing it, you're going to need a complete prototype, or a well developed product. Nobody is going to take you seriously otherwise, or believe you have the capacity to run a scalable business unless you prove it with the product.

You're simply going to be laughed at otherwise, unless it really is the coolest idea ever. In which case they'll still tell you to come back later once you've built part of it. With less honest VCs, they might just take parts of your idea and let someone else do it. Ideas aren't worth much.

But you can receive a lot with a product. While it may be harder to get initial terms, VCs will provide just enough capital to usually justify costs/get you to the next milestone, upon which they can decide to reinvest in a new round of financing or get out if you're not on track and aren't likely to get back. Age doesn't come into it then, if they've committed to the idea.

Sam Altman at Loopt got a $5m series A. Out of freshman year at Stanford. He came out of Y-Combinator originally, which does help though, in terms of credibility.

Other thing you can do is contact entrepreneurs. If you've got a business started and you're young, a lot of them are more than happy to meet. You can work it as an informational interview. They'll also be able to refer you to who funded them or who they met with. Everyone that's gotten funding has guaranteed met with tons of VCs while pitching. Their referrals will also get you in the door to venture capital firms, regardless of age.

Your own professors will know some people as well, depending on your university.