Answer:
score in end zones.
I am essential to life on earth! I am split into thirds. Two thirds are the same. One of the thirds is 8. The other two are 1 each.
I can point in every direction but can't reach the destination by myself. What am I?
I am filled with garb the price is free. Just return what you don't need.
I am the kind of dog that chases anything red.
No matter how little or how much you use me, you change me every month.