How to look like im in shape?

im stout and short (1.73cm), so im trying to get into proportion to look taller but is huge and i dont know how to get rid of it so i need help and tips in getting into shape...cause im performing for my school and i dont want to look retarded...need tips on how to lose weight, how to look proportional and diet tips. please dont tell me to accept myself for who i am...thank you:)