Barcelona confirmed the 18-year-old's arrival from Athletico Paranaense earlier this week, with the Brazilian signing a contract at Camp Nou until June 2031, which includes a €500m (£434.7m) release clause.
Roque has arrived at the club off the back of scoring 28 goals and registering 11 assists in 81 appearances for Athletico Paranaense.
The Brazil international has opened up on his switch to the Catalan outfit, calling it a "dream come true", but he has vowed to remain "calm".
"At first I didn't believe it. After a while, it became serious. I spoke to my father and, when it was confirmed, I was very happy because I was making my dream come true," Roque told Barcelona's official media.
"I've been a Barca fan all my life. It was my only option. It is the best club in the world and it was always my dream to play here. Great idols like Romario and Neymar have also played for this team and they made history. It will be a pleasure to defend this shirt.
"I'm calm. I try not to think too much, not to go any further. I just want to help the club as much as I can to win as many titles as possible.
"This one is clear to me: winning the Champions League would be my biggest dream. I really want to do things well and win as much as possible with Barca. I'm looking forward to learning and enjoying the best in the world."
Roque also said that he is looking forward to playing alongside Robert Lewandowski and international teammate Raphinha at the club.
"Yes, of course. They're all very good, but I'm really looking forward to playing with Lewandowski. And of course with Raphinha too. I'll be fulfilling a dream," he said.
"He told me everything wonderful about Barca and that it's a fantastic club, perfect, with all the facilities to learn and work."
Roque could be involved in Barcelona's next game against Las Palmas on January 4, when the Catalan outfit will be aiming to make it successive wins in Spain's top flight.
Xavi's side will then take on Barbastro in the Copa del Rey before facing Osasuna in the semi-finals of the Spanish Super Cup ahead of a potential final against either Real Madrid or Atletico Madrid.