Another couple of suggestions is to find some duathlons in your area before your race and go watch. This helps a lot if you are new to the event. Stand by the transition area and just take mental notes. Transition is where to can gain or lose time and something you always need to practice. If you do decide to change shoes, I would get speed laces for your running shoes. Sure beats tying knots when you are on the clock. I know you will be able to do this and you will have loads of fun. Enjoy it!