The Lions outhalf, who is bound for French club Racing Metro, revealed he was enjoying the learning curve but it was testing his nerves.
"Having to speak it with a tutor is a different thing to having to do it for real over there in Paris when you are trying to organise a team," he confessed.
He joined rugby stars from throughout the country who abandoned their kit for the black-tie Hibernia College Irish Rugby Union Players' Association (IRUPA) award night in Dublin's Burlington Hotel.
"It will be tough but it is a challenge that I am determined to meet head-on and hopefully it will be a successful one."
Sexton (27) said the last time he had studied French was eight years ago in school. "I'm remembering bits as I go," he added.
The Ireland No 10 made headlines when it was announced that he would be picking up €55,000 a month in Paris, making him French rugby's top earner. "I'm sure the guys with Racing will welcome me into their team and hopefully I can win things with them," said the Dubliner, adding Leinster were still a huge part of his life.
Sexton has already organised a place to live in Paris with the help of the club.
He said there were plenty of English-speaking players to help him settle in, but it was the French that he wanted to impress. "They are the guys who will be running the club, and I want to show them I am there for the right reasons and to win things for them," he added.
Among the others enjoying the awards night were fellow Australia-bound Lions including Brian O'Driscoll, Cian Healy, Paul O'Connell, Tommy Bowe and Jamie Heaslip.
O'Driscoll said he still had no airline tickets booked for wife Amy Huberman and baby Sadie to join him, but that it was a "work in progress".
Ulster No 8 Nick Williams landed the Player of the Year award, after scoring seven tries in 21 appearances.