As a former NGO representative myself for GCI or Green Cross International, I think I can speak for all NGO representatives that international issues matter, as much as issolated ones. Getting involved is the best advice. In that I mean do not slack off on investigating issues. Learn your NGO and what they do, and what they have done to help you decide what issues to tackle. Doing the current events for your NGO will help in this task probably the most.
As an NGO the class assignments as I call them will help you learn your NGO. Plus benefit you when it is time to write your papers. Perhaps contacting your NGO, could help get you resources to better get into the role of your representation. Getting involved with real world events, and corrilating them to other delagates Resolution funding requests. Being said, do not be afraid to mingle with other committees and listen to the funding possibilities. Lastly I cannot stress enough how much easier it is to answer questions in committees, and the General Assembly, when you are an expert on the issues.
The main focus of this course should always be to have fun, and learn about issues the international community face, while also enjoying the conference. Get into your role as fast as you can and carry it forward into the conference. The faster you learn your part the easier it is to play. If dressing the part helps you get into the role, then by all means show up in class with a nice suit or dress. You have millions of dollars to give away, and a responsibility to the children of the world to better their lives. Make it so, you have the power to influence lives.