Hello , I installed LFS recently and i saw that when i configure my pedals (brake /acelerator) the car is always acelerating and the brake acelerates so do the steering Wheel Setup easier

What wheel? If Logitech, install Logitech Game Profiler. Without it, the throttle sticks at 10% all the time.

And of course, when you are in gear, throttle always idles at 5% +/-. Because of engine run.

Try making them a separate instead of combined in Controls

Ah yes. Make sure the axis for throttle brake are not combined, but independant. Also, make sure to test the throttle/brake response and pedal travel inside the Logitech profiler. The graphs will show the travel, make sure when you are idle, the graph axis for Throttle is also at 0%.

it´s a Ferrari Red Legend Thrustmaster , and the problema is the car is always reving and even with a gear put on he dont go only when i brake he goes .

fix already explained by microspecv