Whats the quickest way to burn fat around my upper and inner thighs? HEEELP!!!?

okay well first off im not fat! i just want to get back in shape..well i want to be more fit and im only 13...well i really want is to be able to fit back into those cute short shorts from hollister...and i also want to know how long it will take...to sculpt my legs into a y tight and fit look...but it seems like everything i do it dosent work or it takes to long...and im extreamly busy so i just need a quick way to do this and still get the results im looking for..and like i said im only 13