Day 2 of chess summer school is a basic ending of King and Two Pawns vs. King and One Pawn. You have to learn how to count!
The first step is to occupy h6 with your king. You do that by gaining the opposition with move one: 1.Kg5 Kg8 [The pawn check fails: 1...h6+ 2.Kf5 Kf7 3.h4 Kg7 4.h5 Kf7 5.g4 Kg7 6.Ke6 Kh7 7.Kf7 Kh8 8.Kg6; Black could set a trap with 1...Kf7 2.Kh6 Kg8 3.h4 Kh8 4.h5 Kg8 but now White sidesteps it with 5.g3! Kh8 and now 6.g4 wins. If you play 5.g4 right away and do the march down to g6, after the exchange on g6 there will be a g7+ which leads to stalemate. That’s why you count it out!] 2.Kh6 Kh8 3.g4 Kg8 4.h4 Kh8 5.g5 Kg8 6.h5 Kh8 7.g6 hxg6 8.hxg6 Kg8 9.g7 and wins.