The Magpies won the Championship last season under the Spaniard but, in their return to the top flight, have failed to score or pick up a point so far.
Benitez has previously criticised Newcastle's lack of spending this summer, with owner Mike Ashley giving an interview in which he admitted that the club had to take a thrifty approach in the transfer market because he cannot compete with the league's financial heavyweights.
"My experience in the Premier League is that you have to take your chances because, if you make mistakes you will pay for that," Benitez told Sky Sports News after Newcastle's 1-0 defeat at Huddersfield Town. "It's maybe because it's a learning process so we have to learn quickly, maybe it's too soon for us."
Asked if that learning process would take longer than people expect, he replied: "Yes, for sure. We will need time, but I am sure we can improve. Does the team have goals in it? Yes, I think so. I think we will improve, and we will create more chances and score goals, for sure."