The Dutchman has taken over as United manager after leaving Ajax.
As reported by O Jogo, Fernandes said: "Whatever it is, we're going to try to win every competition.
"It's a new project, it's something that starts from scratch and we have to give it time to flourish."
On Cristiano Ronaldo's future, Fernandes added: "What I hope is that Cristiano will be there with me on Monday, that he's one of those who will come back later because of the Seleção's games and I'm not waiting for nothing more than that.
"As far as I know there is nothing more than that, but everyone knows their future. I don't believe the club is willing to lose a value like Cristiano."