Making for the first time, how do I keep the outsides from sticking to each other?
I'm not sure what you mean - are you talking about stacking the cookies after they are finished?
yes I need to put them on a tray to be served from.
Put a piece of plastic wrap, waxed paper, or sheet of food tissue wrap between the layers. Trim so it's not sticking out too much. Don't worry about it not looking "perfect." You're the only one who will notice!