Jacob Ramsey gave Villa a first minute lead, with Morgan Rogers also scoring for the hosts. Mathys Tel struck late for a Spurs consolation.
Emery said afterwards: "Morgan is performing fantastic. His commitment to do his task every day from the first minute to 90 is great. We did a lot of positive things today.
"It will be very demanding for us in this competition, so we will need to improve and increase our level. We are with the motivation to get something in this competition as well as the Premier League and Champions League. We still have a lot of work to do."
On Ramsey, he stated: "He played really well. We are happy when the player is scoring. He had more chances. Of course, we need his best performances from Ramsey. He is getting better and being consistent without injuries. We will need players who are physically good for the rest of the season.
"There are players coming back in the coming weeks. We also have players like Donyell Malen, Andres Garcia, Marco Asensio and Marcus Rashford and hopefully, we can build the team in the structure we want to create."
On Rashford's debut, he added: "We have to protect every player and try to adapt them into our structure and use their skills. Asensio, Rashford and Malen are versatile players in the attacking third. We can feel confident to have them.
"We are very demanding in our way because we want to be in the top six or top five in the Premier League as well as in the Champions League, where we are in the last 16."