Haaland made his league debut by scoring a goal in each half, including a penalty in the first period, as City began their title defence in impressive fashion at the London Stadium.
"We didn't have any doubt a guy who has scored goals since he was born that he would score goals here," Guardiola told Sky Sports about the 22-year-old striker who joined City from Borussia Dortmund in the close season.
"Haaland gives us his qualities. We are not going to change much, we will adapt, we know we have a threat there. He is an incredible deep runner and finisher.
"He is adapting perfectly to the way we want to play. We are going to find him more and more and hopefully, we can give him the opportunity to score more goals."
West Ham manager David Moyes said his team had been outfoxed by City, who dominated possession in Sunday's game.
"They were so good. I felt that tactically they completely outdid us today," Moyes said.
"It was a case of trying to stay in the game. It was only 1-0 at halftime with a penalty and it gave us an opportunity and a chance.
"I felt like we had not played well enough so I wanted to try and change the run of the game. We got a little bit more of the ball for about five minutes. They were far better than us and we couldn't cope today."