The England winger joined United from Borussia Dortmund this past summer in a deal worth £73m.
Speaking to UMM, Sancho has vowed to replicate his form from Dortmund at Old Trafford.
He said: "I haven't stopped smiling. I'm just happy to be here and be part of the Red Devils and the team.
"Especially when I made my debut - the lads have been very good with me and made it easier.
"I'm going to keep playing my game. I'm not going to change what I've been doing over in Germany. I've just got to bring it here and hopefully I can show the fans what I can deliver."