Ok first of all, what do you mean when you say it's 2-sided?
Second of all, binding is usually attached as one long strip. You sew several strips together with a diagonal seam, then attach it to the quilt. When you get to a corner, you flip the binding away from the quilt, then fold it back down on itself, turn the quilt and keep sewing. There are gobs of video tutorials on YouTube you might want to check out.