Back to square one
Starting over after a failure.

Burn the midnight oil
To study or work late into the night.

Learn the ropes
To understand how to do something.

Hit the books
To study hard.

Teacher's pet
A student who is favored by the teacher.

A clean slate
Starting fresh without any past mistakes.

School of thought
A particular way of thinking or a group of beliefs.

In the same boat
In a similar situation as someone else.

Pass with flying colors
To succeed with great distinction.

The ball is in your court
It is your decision or responsibility.

Cut class
To skip school or a class.

Teach an old dog new tricks
It’s difficult to teach someone new things when they are set in their ways.

Play hooky
To stay away from school without permission.

School of hard knocks
Learning from difficult experiences.

Take a rain check
To postpone an invitation or plan.

Put on your thinking cap
To think seriously about something.

Ace a test
To do exceptionally well on an exam.

Keep your nose to the grindstone
To work hard and diligently.

Make the grade
To meet the required standard.

Rise to the occasion
To perform well in a difficult situation.