A good (i'm talking GCSE/Alevel) knowledge of physics and maths helps with understanding how planes work. And also helps you when you need to manually work out things such as bearing, heading, fuel consumption, fuel requirements.
But qualifications you will need:
Most new pilots these days will have A-Levels, i would suggest you go for these (study subjects you enjoy, math's and physics would be a bonus but not a necessity) But at a minimum you'd need 5-7 GCES's at grade C or better including english, maths and a science (preferably pysics and it should preferably be a pure science)
Once you've left school its time to get your flying licences and medical:
A Class 1 medical
PPL
CPL/IR(the course should include a night rating)
ATPL ground theory
The above will set you back around 40-60k pounds
Once this is done you'd have everything you need to become an airline pilot. you've got a lot of time which gives you plenty of time to explore your options.