The young Three Lions trailed 2-0 at half-time, but scored twice early in the second-half to secure a point in their game at Sincil Bank.
It was their first match in a four-team international tournament being co-hosted by Lincoln City, Scunthorpe United and Grimsby Town. Portugal had defeated Australia 4-3 earlier in the day at Glanford Park.
"To come from 2-0 down I thought we showed a lot of fight and a never-say-die attitude, which is very pleasing," said Peacock.
"We've come out of the game with a lot of plusses, certainly in the second half. It's been a fantastic learning curve for the players.
"To be fair to Turkey, though, they've got some good players and when given that amount of space to play, we couldn't quite get near them in the first period and consequently we found ourselves 2-0 down."
England continue the tournament on Friday night when they take on Australia at Blundell Park, before playing Portugal at Glanford Park on Sunday.
"In tournament football it's always important that you get something from your first game," added Peacock.
"We've done that but we need to build on it and get better. It's always nice when you finish a game strongly, but we can't rely on a strong finish in every game and we need to start better against Australia."