I think I rolled or sprained my ankle. Do I have to wrap it? I don't know how to wrap an ankle.

Yes. The best thing is to ice, ace wrap, elevate right away. There is usually a picture on the box but you an simply start just below the toes and wrap around overlapping the ace by 50% until it goes above the ankle almost to mid calf. Not too tight! just enough to apply gentle compression. Pain not letting you bear weight is a sign to take you to the doctor's office.