Using keywords in your domain name will improve your chances of being well ranked for those keywords, but you need to provide useful content (that also contains those keywords) in order to rank well.
Google's mission is to order the world's information by returning relevant information to anyone who seeks it. If your site provides nothing of relevance beyond the domain name, Google has little reason to return it in search results.
Also note that Google is considering reducing the weight placed on keywords in domain names so, even though you might benefit now from using this approach, don't bank on it lasting forever.
For general advice about improving page rankings, see this question.