Help with pattern

I am searching for a hat pattern that I can make. I still have a bit of trouble understanding the patterns. Can you look at this and tell how much yarn would be needed for this hat? I think there is a choice and my choice would be a bulky or medium. Where does it say how much if I decide I have to by yarn?

It actually doesn’t give you a number. The first paragraph says one standard skein usually makes a hat. So don’t buy a tiny skein or use leftovers unless you want to stripe.