Hi, Brooke ... that's not an option on Trulia, as only listings uploaded via direct feed from licensed real estate agents/brokerages are accepted.
You can list your home for free on Zillow, though you want to be careful what the Zestimate is for your house as that will be attached to your listing below your sales price. As Tim mentioned, you also can list your home for sale on craigslist.
Honestly, you'll get more traction with a traditional listing in the MLS; if your market is active enough, you might be able to go it alone. If the market's quiet, though, that's going to be a different story.