After purchasing a used vehicle 2020 model, and after setting in owner's garage for two weeks, the vehicle was driven at slow speed thru two intersections after a complete stop. at the third intersection stopsign the vehicle started moving slowly with the brake on. the brake was then applied much harder very forcefully to avoid a collision. the vehicle continued moving at a creep striking the rear of the vehicle that was passing thru the intersection. the vehicle then continued on..with the brake pedal still applied at floor level and only stopping after hitting the ditch. Problem was----BRAKE PEDAL GOING TO FLOOR AND NOT STOPPING VEHICLE.