2 kings and a pawn

So I look this up but it was confusing because it had different exceptions and I did not really understand it. So I am playing as white and I have my king on h2, black has a pawn on f7 and his king on g6, that is the only pieces left and it is blacks turn. So my question is can I stop black from promoting his pawn and force a draw or will he be able to promote no matter what I do?

Black should be able to win with correct play since he can easily gain the opposition from the above position.

Although rook pawns never win if the king can get to the queening square before the pawn can. 

If the side with the pawn can get his king to a key square, then they can force the promotion and win.  In this kind of position, the key squares are shown, marked by knights here:

The other concept you need to understand is opposition as shown in the next diagram.  Opposition is a term for when two kings battle eachother for position.  If you have opposition the enemy can't stop you from breaking through to new squares.  Without opposition you cannot make any headway.  There is more to opposition than the below (diagonal and distant opposition which you can wiki  or google).

So now finally to your position.  Black can achieve a winning position right away by playing Kf5 or Kg5.  Notice the key squares will change as a pawn moves up the board which is why to win you need your king to stay in front.

What if black's king can't get in front of his pawn?  Then it's a draw. To draw positions like these you have to keep the enemy king off the key squares.  I'd say the position beginners most easily mess up is when the enemy king takes opposition from behind the pawn, the most principled move is to step straight backward to be able to take back the opposition.