Hello Jacob,
First of all, making a web site from scratch (especially the one that would be as feature-rich and user-friendly as Facebook) will take way too much time, trouble and money. But that is of course unless you have extensive knowledge of PHP/MySQL (for building a platform), HTML, CSS and Photoshop (for designing a competitive template). Another difficulty is a constant need for adding new features, fixing bugs and optimizing a server to comply with the appetite of your audience and industry trends, and to handle the traffic loads.
Even mature developers with pretty much experience in web programming who build online projects for their clients, prefer to work with ready-to-use dating and community software, as that allows them to skip the stage of reinventing the wheel. The main aspect to pay attention to is a 100% open source code that you will be able to modify the way you want as soon as you have enough skills. Only this algorithm will help you create a really competitive and full-featured social network within a reasonable time-frame.
You can go for a paid full-fledged community and dating software solution - SkaDate Script http://www.skadate.com . It comes with a 100% open source code (PHP), and a set of features and templates that will impress you and your future members.
Or, which would probably be an even better solution for you - create a network at http://wackwall.com for free. And later, when you have enough skills in PHP, download its source code (also for free), which is about to be released ( http://www.openwack.org ) and modify it according to your conception and preferences.