Do you believe in the time-line of the creation story as told in Genesis? Do you believe that the Earth is 6000 years old +/-? If you do, you are a Young Earth Creationist (YEC). That's the definition.
I don't have any idea how old the earth is so I can't be considered a YEC. But the timeline in Genesis does say God created the heavens and the earth. It also states that He created humans as humans. Simple enough.