There are no "secrets" or shortcuts to success in your studies.
All you need to succeed is the right mindset and the right techniques.
These are what you will learn here...
Matthieu Chan Chee
General Tips
Dig deeper and don't give in.
Be an independent learner.
You can perfectly well go to competitions, do extracurriculars and have fun with your friends. Laureateship should not be an obsession.
Becoming a laureate depends a lot on luck and in the end, it all boils down to getting a university scholarship. There really are loads of other scholarships you can get (those mainly depend on the extracurriculars you did) so don't put all your eggs in one basket.
And remember: if you're not a laureate, it's okay.
If there's anything, feel free to reach out https://mchanchee.github.io/
Subject-SpecificTips
Computer Science
Code a lot and it'll come naturally.
Mathematics
Have all the math papers on your phone. Once you finish what the teacher assigned for class time, do math questions.
Physics
Train your problem-solving skills by doing Further Maths mechanics, Pre-U and British Physics Olympiad questions. Lots of laureates mess up the practical. Of course, do your best not to but if it happens, don't give up.
General Paper
Compile a bunch of knowledge for every topic. Model UN helps a lot to know about global affairs.
French
Pay attention to detail and hone your grammar to perfection. Know the French equivalent of useful English terms e.g. UN (adj for United Nations) in French is "onusien".
Here is an inspiring Story that Matthieu is sharing with you...
There had previously never been a Computer Science laureate so we couldn't know whether it'd happen. If your subject combination is unusual, don't worry. Just do what you love doing and dare to go against the odds.