A simple idea for the entrance is a balloon arch. Your daughter's school probably has a helium tank, and if not most businesses that rent tanks will lend them to schools free of charge. Purchase balloons in school colors. Thread a needle with fishing line or heavy twine (measured to the dimensions of the doorway or entrance). As you blow up the balloons with helium and tie them off "sew" them together thru the "tail" of the balloons. When the string or line is completely full of balloons, fix each end to one side of the doorway. Let the helium do the arch work for you! It will look great!