You need to rephrase your question. It does not make sense.
You can say "Je vais au lycée" in French to mean "I go to high school".
Le lycee if French for "the high school."
In French, haut école or l'école is high school; le lycée is college, or senior high school.
In French, you say "lycéen" for a male high school student and "lycéenne" for a female high school student.
"à l'école" means "at school" in French.
I must go to (senior) high school tomorrow
'bac' is the abbreviation of Baccalaureat, the exam taken by French students doing their final grade in high school.
junior high school is called 'le collège' in French. Senior high school is called 'le lycée'
Un lycee.
I'm going to school. (le collège in France is the equivalent of junior high school in the USA)
The name of the exam taken by French students after high school is called the Baccalauréat.
It's not French