City won 2-1 as Rodrygo's opener for Real was canceled out by Nico O'Reilly and an Erling Haaland penalty - all before halftime.
“Sometimes when you score a goal or when you play you find a goal and after you find the game or the way we have to play,” he said.
“Until the goal we scored, they were much better. We could not control them, we tried to have the ball but not with intention to be aggressive with it. Every time we lost the ball they punished us, especially with Rodrygo many times.
“The second half was much better. In the end it was good to score a goal because it helped us to be there.
“Jeremy (Doku) was outstanding today and a good experience here for many new players, coming here to this stadium. Everybody feels the pressure to do it. It will be a good lesson for the future.
“That level is not required to compete for the last stages but maybe in February we will be better than today.”
Asked what winning at the Bernabeu will do for City's belief, Guardiola was cautious.
“Winning in the Bernabeu is a big big task, really big task, especially in this competition, don’t misunderstand me,” Guardiola added.
“But at the same time in February, March we are able to go through the level to arrive in semi-finals, finals, requires a better performance than today. It is not enough to be there.
“There are many good things, I am so pleased for the players for the effort, soul and heart and how they run but here and Anfield and PSG, Dortmund, Arsenal, Barcelona, knowing the players we will be better. We will improve, that’s for sure.
“Five, six or seven players come here for the first time and we have to live that experience. Experiencing winning will help us.”