Concentrate on school as noted above; get a plan of action and join Air Cadets perhaps? Consider joining the UAS if military interests you prior to airlines. Speak to people at flying clubs and go up with them if they offer, ensuring that logged hours remain minimal if you are aiming for sponsorship. Join the Royal Aeronautical Society at university to get an insight to all areas of the business. Bear in mind that the training materials may change prior to you embarking on the course, so try not to spend cash on what may become obselete in some aspects.