1.) A normal attire will do, you dont have to purposely wear formal shirt. This is because after this will be the beginning of orientation week, you guys will undergo series of activities, and you must wear the shirts they give you. Once you enter the campus, you should make your way to your residential college.
2.) Things that you listed there are needed, but not for iron. Imagine you are about to move to a new room, and you are going to stay for 1 semester on your own. If you feel that quite hard to bring them here, you can buy all of them after you arrive at campus. Grocery shops are available around UM campus, such as mid valley and PJ area.