cruise control

how do i use it? i ask cuz my car still accelerates when i let go of the accelerator, someone told me to check IM for cracks, others say the flap in the throttle body doesnt clos all the way, it really gets bad after i fill the car with gas, when im near empty its not too bad

But i need new rotors as well and its hard to stop, so the acceleration prblem and no brakes isnt really safe.
if anyone has and input on what i should do let me know