a pen and paper, note down key vocabulary and test yourself.
Never just sit down and read the textbook for a set period.
Focus on tasks, not time.
If you just read notes you'll only retain about 10% of the information.
Is GCSE French hard? How hard you find it depends on many factors, like the learning method you choose, how much you enjoy the process, and your motivations.
French is a pretty tough language to learn for several reasons