The Quins flanker was an integral part of the England U18s set up last season, playing in eight of their nine matches including the three-game tour of South Africa.
Most of the touring party have made the step up to the U20s squad, raising concerns over their ability to perform against players a year older than them.
But White, who started at blindside against Scotland on Friday, is confident they can help England retain their Six Nations crown as well as being contenders at the Junior World Cup in Manchester in June.
“We are under no illusion that the U20s will be a big step up but we’re confident we can perform at this level,” he told The Rugby Paper.
“There are a lot of players in the squad who toured South Africa so we pretty much all know each other and that really helps when it comes to team spirit.
“Our aim is definitely to win the Six Nations and, hopefully, carry that form into the World Cup in the summer. At the start of the season, all I wanted was to make the squad. I managed to do that and started the first game of the Six Nations. Now I’m hoping I can keep the shirt and help the team be successful.”
White ended his schoolboy career as captain of Epsom College last year, losing only two games all season, before linking up full-time with the Harlequins academy in the summer.
Making the step up to senior rugby was, as he expected, a physical challenge but he is pleased with his progress.
“This season has gone really well for me so far and I’ve managed to make my first team debut in Calvisano in the Challenge Cup,” he added.
“We’re lucky at Quins that the academy boys train full-time with the first team so I’ve been able to learn a lot from the players around me like Luke Wallace who’s been my mentor.
“We’re quite different in the way we play but there are a lot of things from his game that I can use so it’s a good combination.
“I’ve started the season playing for Worthing which was very good for me to get used to senior rugby before going back to Quins to play in the A-League.
“Playing in the National Leagues allowed me to see the physicality you need to play at this level. I expected it to be tough and the body was a bit sore after the first few games.
“Getting up to speed with men’s rugby is my main target this season before pushing on next season.”