How to lose belly fat & waist size without gaining muscles?

My belly has fatt and i just want a flat stomach.
My waist is sorta wide? O_o & i dont like it
Im planning to become a teen model for my career
& Im 5’4 right now and trying to be 5’8 soon
I dont wanna gain any leg muscles cause my legs will loook huge O_O
& i want skinny and long legs.

how to do i lose belly fat?
& waist size?
[without gaining muscles]