When I turn the steering wheel and use the brake, my car makes a grinding noise.
Sounds like your brake pads might be low. The brake pad has a semi-metallic friction pad that makes contact with the rotor. When this pad wears out, the metal backing plate that it is attached to makes contact with the rotor. This is when you hear the grinding sound of the metal to metal contact. A mechanic, such as one from YourMechanic, will be able to do a proper brake inspection and determine what needs to be replaced or repaired.