Hi Francesca,
Although there are no formal educational qualifications required to be a pilot, most airlines/'sponsorship' schemes would require a minimum of 5 GCSEs and 2 A levels as a professional pilot.
You also have the choice of full time Integrated training or part-time Modular depending upon your circumstances. Both, long-term, will cost a lot of money. I guess you are more likely to follow a modular route, in which case your first step should be to gain a PPL!
There are then further options depending upon what kind of flying you ultimately wish to do.
Regards,
Pushapproved.