If Executive Orders immediately became law, Guantanamo would have been decommissioned eight years ago, when Obama signed the order. 
No matter how much you and he might wish it, Trump cannot unilaterally create law. He requires Congress for that. Congress shut down government, rather than cooperate with Obama. Trump may be running from the same party that has control of that house, but he has few real friends there, and the Republicans have their own agenda.
His Executive Orders are not much more than 'memos' to Congress on what he'd like to be discussed and acted on. Whether they comply is up to them.