The new Los Che coach was unveiled yesterday in Valencia and said: "I have wanted to manage in Spain and this is a great opportunity at a great club. I have been waiting for this opportunity and I am happy."
Koeman, 44, added that he hopes to meet the expectations of the club's "demanding support".
"We need to find a balance, entertain the public and get results," he said.
"Valencia have quality players and the fact that the club has a demanding support is not a problem."
"It is too early to say. In football you can win with different systems and it is the players who define which one you use," he admitted.
Koeman takes over from interim coach Oscar Fernandez on Sunday, a day after Valencia's Primera Liga clash with Real Mallorca, and will sit in the dug-out for the first time in Tuesday's Champions League game with Rosenborg.
"From Tuesday we'll have a much better idea of what we want at Valencia," Koeman continued.
"This is a hard moment, but I am excited about the challenge of putting Valencia back where they belong, up there with the big teams in Spain. To do that, I need the help of all of the team, the media and the fans.
"The championship is long. We have only played 10 games and that means there are 28 left. That is a lot of points and we are only seven behind (Real Madrid). That is a very small difference."
"He is a coach of international prestige and also had success as a player," Soler said. "We think he is the right man to return this club to a prestigious position in Europe."