Get in front of your users!
As a startup founder, no matter how far it is outside your comfort zone, the best way to get your first customer is by getting in front of people.
I'd suggest joining your local Chamber of Commerce and attending local meetups. In most cities, you should be able to find at least a small group of like-minded people interested in the problem you're solving. If you can't do it in person, consider doing a webinar or Google Hangout instead.
If you know who your user is, your next step is to make sure they understand what you're selling. The best way to do that is by asking smart questions, and ultimately, testing and refining your elevator pitch.
Not up to in-person networking? Find a co-founder who is! ;)
Need help finding meetups? Want to learn how to quickly, easily and inexpensively host a webinar or hangout? Feel free to schedule a call with me for any questions you may have.