Some background:
I'm 15 years old, attend high school, do well in terms of grades and extracurriculars (business clubs/competitions), and also am a pretty good front-end developer experienced with HTML/Jade,CSS/LESS, JS/jQuery/AngularJS, and Phonegap/Cordova. I've worked on several web projects in the past, such as http://teen2geek.com, and my portfolio is at http://krrishd.github.io, just to get an idea of what I can do in web development (not so good at the backend though).
I recently took part in a social entrepreneurship competition to prevent suicide, and I envisioned a specific app, and the idea won a grant. This app is somewhat similar to some social networks you've seen, and is a bit complex to develop for a front-end guy like me. The grant is a "micro-grant", so it isn't anything substantial, and I'm not sure if outsourcing can retain the quality necessary for such an app.
What do you think I should do?
Two reasons:
1. You're young and still figuring out what you love doing; no better time to experiment and learn. I still have fond memories over the php site I wrote in high school. You could visible tell which functions were written at the beginning of the project versus the end because you'll improve drastically. [1]
2. The project will be more successful with someone who cares for it. Hiring a contractor will make it difficult for you to maintain and improve. Contractors will also expect a specification with penalties if you need to change it. My guess is that you're still experimenting with what can best serve the community so this probably isn't a good fit for contracting as well.
[1] Recommended tech stack (optimizing for documentation and availability of help). Ruby, MongoDB, Heroku (or if ambitious, Linux on Amazon EC2 + nginx). Everything else is pretty similar so once you learn these, the concepts apply reasonably well.
p.s. If money is a concern, you should look into contacting some companies PR/DevRel people and see if they are willing to donate some compute time or services to your cause. (It's probably doing this after launch and getting a better sense of usage and will be easier to convince them that you're legit).