question about using localbitcoins.com

I´m a U.S. tourist staying in Mendoza, Argentina. I want to sell some bitcoin using localbitcoins.com. There is a buyer here in Mendoza offering a good price and I want to contact him.
Localbitcoin requires me to put some bitcoin in a wallet before I can contact a buyer. It just shows me a bitcoin address to send the btc to, with no other explanation than that. I don´t want to just send money off into the void. I have no idea I´ll be able to sell that bitcoin. If nothing happens with this sale how will I be able to retrieve those bitcoins? The website just says send it in, they don´t say they´ll ever give it back.
Edit: I am now reading the faq about how this works. I´m a total noob regarding localbitcoins or btc transactions for cash in general. I´m sure after I get a handle on it all it will seem quite simple in retrospect.