G has 16 elements and H has 4 elements....so G/H = 4?

Now I have what seems like a corollary in my book, but not stated as...it says "a group of order 4 is isomorphic to Z4 or Z2+Z2 (direct prodcut)"...so would the first part be yes? Maybe I am over complicating things...

and then on the second part

k = <(1,2)>

How do you find out how many elements a generating function like K has?