Open Question: Virtual Stock Exchange?

Ok this may sound like a stupid question, but my macroeconomics class is playing a game on virtualstockexchange.com (a site that reflects the true stock market) and I wanted to know, when I put in an order to sell it doesn't go through for about 20 min, and then the order is in pending mode for about another day or so. When I place the order to sell, will it sell at the price it was at when i placed the order, or will it sell at the price it's at when the order is finally complete after a day or so? Also, if anyone could give me good advice on companies to invest in whos stocks look hopeful that would be great too. Thanks!