never done this before, do it slowly. use the paper's edge as your guide.
open the paper and cut along the line. your paper should now be square [or square enough].
the crease that you made in step one is part of the process of finding the center of the square. normally one would just fold the paper again, making another crease from corner to corner on the paper, but since we are not making a four or eight sided object, we will not do this because a second crease from corner to corner will not help us in making a 6-sided object.
the first question i have is: can you see the 