i don't know what it is in the UK but over here in Australia, you go to a training school, you go for your solo licence then private than commercial, after that you have to do so many hours of night time flying etc. go to your local airport they should have some training schools there.
you need to go through the air force or coastguard and you need 150,000 or more hours of twin engine aircraft flight time good luck
um don't do drugs!!!