Fulham were beaten 2-0 by Chelsea in Sunday's west London derby to leave them propping up the English top flight with eight points.
However, Ranieri insists that he is pleased with what he has seen so far from his new club and remains confident that they will avoid the drop.
"We made a mistake for the first goal and then in the second half we played much better," he told 'Sky Sports' after the game.
"We created some chances and, of course, when you play against a big champion it's something we had to do. We are improving. It's a positive step but, of course, we have to react immediately.
"I am feeling good because the second half we created good problems for Chelsea and now we have to continue in this way.
"I have to change, to improve and work hard. I have very good players and I am very convinced we can do something good this season."
Next up for Ranieri and Fulham is a home game against the Italian's former club Leicester, with the man himself admitting it will be an emotional day.
"It's a very emotional game but it's very important for us to make a point. I am positive we [will] have a very good reaction and I'm sure we will play well," he explained.