The sides meet at the Stadio Artemio Franchi in Group K on Thursday with Montella's side having failed to hit the ground running in Serie A so far this term.
A 2-0 defeat to Roma was followed by a goalless draw against Genoa, although the hosts will be favourites to overcome their French opponents this week.
Guingamp - Coupe de France winners last term - have lost three of their opening five Ligue 1 games.
And Montella is eager for Fiorentina to get off to a good start and feels a lengthy venture in the competition is possible.
"It is the start of the Europa League and we care about this competition," the Italian explained.
"We have to give our best to go as far as possible. We have a competitive squad capable of doing well in Italy and Europe, but first of all we've got to win tomorrow.
"Guingamp are a young team full of enthusiasm, so it will be complicated, but we must play like Fiorentina. If we create the same number of chances as we did against Genoa on Sunday, then I'll be happy."
With Fiorentina yet to score in the league this season, Montella would not only welcome a win but some goals from his misfiring strike force as well.
Mario Gomez is back at full fitness, but Giuseppe Rossi is unavailable due to injury and Juan Cuadrado is yet to hit top gear following an impressive World Cup with Colombia.
Montella stated there would be changes from the draw with Genoa ahead of a busy fixture schedule.
"In order [for him] to score, Gomez has to play... but I will decide tomorrow whether he starts, as we have a long run of important games coming up," Montella continued.
"I don't generally like to revolutionise my line-ups, but there will be a few changes compared to Sunday.
"We did well against Genoa at the weekend, but were only lacking in terms of finishing the chances. That's something we already struggled with at the end of last season."