Have a look at gliding. Your nearest club
https://esgc.co.uk/ offers a Junior scheme, making it affordable. Also there's plenty of other people your age who do gliding so can make likeminded freiends. Also worth looking at scholarships and bursaries which are well worth applying for
https://airleague.co.uk/our-programm...-and-bursaries &
https://www.airpilots.org/scholarshi...-scholarships/. BA has openly admitted that doing Gliding is a big tick box on your CV and will only help you. As others have also said, go to PCL at London Heathrow and get a Class 1 medical done when you can before spending any money. Good luck!