Barca agreed to a deal to sign Fernandes from Palmeiras for an initial €7million in January, but with that transfer not going through until July he joined Real Valladolid on loan for the rest of the 2019-20 campaign.
However, the midfielder was unable to make his debut before the coronavirus pandemic brought the season grinding to a halt in March.
Despite being unsure what his short-term future holds, Fernandes is confident he will enjoy a successful career at Camp Nou.
Asked about the prospect of playing alongside Messi, Fernandes told Mundo Deportivo: "I can't explain it. To think that soon I will be playing with the best player in the world, I don't even know what to say.
"It is a dream to get to that great club and have the opportunity to be part of it.
"My goal is to play for Barcelona. My contract [with Valladolid] ends in June and I want to be in Barcelona, it is every child's dream.
"If I can't go to Barcelona now, I will continue learning at Valladolid or at another club where they value me. I am happy to be here and playing in LaLiga.
"I think I'm going to succeed at Barca. I have the potential for it. I think I fit in with the style of play.
"I hope I can be there and stay there forever and make history at Barcelona."
He added: "I am very happy because the club showed interest in me. I have great qualities, but I am going to evolve much more there.
"I hope to be there for a long time and I hope to win many titles and bring much happiness to the club and the fans. If the club is happy, I will be."
"I am a box-to-box midfielder, but I also like to play in a holding role protecting the defence. I am a technical player," he said.
"I know I still have a lot to learn, I am aware of it and I am trying to improve here at Valladolid, but I think I am going to mark an era at Barcelona.
"I need to finish better, play quicker. I think I am a good marker, I have good positioning, a good pass and the most important thing is will and I have the will to improve and do my best for Barcelona.
"I like Sergio Busquets' way of playing a lot and I always noticed him, Xavi too. I'm going to try to do my best to be able to get closer to the level of these great players, knowing that I still have a lot to learn."