Taking place during the 30 years war in Germany, this 2008 Thriller starring Daniel Brühl is a German remake of a Czechoslovakian film from 1978, where a boy learns of the dark arts from a sorcerer. Fun side note: the song in the end credits is called Allein Allein, by Polarkreis 18. (An earlier version of this post mistakingly noted that the band Schiller was associated with this particular song.)
Krabat is played by David Kross, who also was cast in a 2002 version of Hilfe as a kid, which was his first acting job. He later went on to play in The Reader, Das blaue vom Himmel, War Horse, Trautmann, and most recently Betonrausch (to be released 2020).
The evil sorcerer is played by Christian Redl, who can be found in Tattoo, Der Untergang, and Die Schlachtinsel, among many other TV movies and series.
Other familiar faces include Anna Thalbach, Charly Hübner, Daniel Steiner, and Sven Hönig.
There is a point of drinking to the point of illness about 33 minutes in. This scene is very short. Other concerns in this film for teenage viewing are also fairly mild, and well spelled out at IMDB.