Sergio Aguero’s finish and Lewis Dunk’s own goal secured the three points for Guardiola’s men against the Premier League newcomers.
“We’re here to win games and we won the first one – but it’s just the first one,” he said.
“Against newly-promoted teams it’s always complicated – they defend so deep, with 10 players – but we were able in the end to win the game.
“We have to learn to attack better if teams play in that way, the big teams have to handle those situations. I’m happy with what I’ve seen today.
“With the results this weekend, I’m happy to win away.”
Aguero’s partnership with Gabriel Jesus looked threatening throughout, with Jesus having a goal disallowed for handball and Aguero wasting a clear chance before his eventual breakthrough.
“They had chances, both of them, but of course we need goals,” said Guardiola.
“These two guys have goals in their blood, they live for that, but to score goals we have to try to create.”
City captain Vincent Kompany, who will be hoping for an injury free season, was also pleased with the perseverance his team displayed.
“We had to be patient, in the first half they were well organised, we could see they had a clear game plan,” he said.
“But we’ve got quality in the team and eventually it made the difference.
“The season is going to be long, we had a five-minute spell under pressure but we put our bodies in and made important tackles.
“There are a lot of positives to take out of this game, building on what we did in pre-season.”
Brighton manager Chris Hughton was pleased with his side’s efforts to contain City and said: “For 70 minutes I thought we were good.
“There’s only one way a team like ourselves can play against them, and that’s to keep it tight and frustrate them. The one time we got stretched, they capitalised on it.”
Asked how he will pick his team up following the defeat, he added: “It’s reasonably easy after a game like today.
“It doesn’t need a scientist to determine that we’ll lose more games this season than in the last couple of years.
“We’ve won a lot of games – particularly here at home, it’s been a bit of a fortress for us – but if you want to play in the top division, you’re up against the top teams. You need to put the defeats and the poor performances behind you and look forward to that next one.”