The Portuguese is preparing for his first derby since arriving at Old Trafford last month -- with both teams desperately in need of a win.
United, 13th in the table ahead of the weekend fixtures, have won only once in four league matches since Amorim joined the club.
Pep Guardiola's City have just one victory in 10 games in all competitions but are still eight points ahead of their rivals in the English top flight.
United were buoyed by Thursday's 2-1 Europa League comeback win at Viktoria Plzen but they desperately need to turn their form around in the league -- they have their lowest points total after 15 matches since 1986.
"I am always looking forward to coaching Manchester United, especially in the derby but we have so much to focus (on)," United manager Amorim told MUTV.
"We are focused on improving day by day, and we want to see different things.
"I think we did a good job in the first half against Arsenal (in an eventual 2-0 loss), so we have that ability, we have players to do it, and we will try to do it again and try to win the game."
The former Sporting Lisbon boss said it was vital to create a winning culture after United's Europa League victory in midweek, during which they recovered from a goal down, thanks to two strikes from Rasmus Hojlund.
"You don't (get) carried away about the winning -- we should win this type of game that we had Thursday -- so now we're going to another game we need to win," he said.
"We lost the other two in the Premier League (Arsenal and Nottingham Forest). We have to have this feeling of winning these kind of games, and we will be ready.
"Of course, we know that we have a lot to improve. A lot of things are changing here but we will fight for the game."
United have had some torrid times at the Etihad Stadium in recent years, with 4-1, 6-3 and 3-1 defeats following their last win there in March 2021.
Guardiola is in the middle of his toughest spell since taking charge in 2016 but Amorim said he would not be distracted by City's problems.
"I have a huge respect for Manchester City but I'm just focused on Manchester United," said the Portuguese, who inflicted a 4-1 defeat on City last month in his penultimate match as Sporting boss.
"We have so much to do here, in my mind only (this) exists.
"Of course we need to have a strategy, we need to understand the opponent, but my focus is just Manchester United. We just want to improve and to win games."
