Hi, i'm trying to set up my controller (xbox series), i know it's not the best choice, but i wanted to try it out. The thing that i need to help with is the steering setting, cause it's spastic and too fast.
is there a way to make the steering speed slower..

I'm having the same problem. I've read through the forums and tired every suggestion but still the slightest touch and the car is all over the place. I'm still working on it but its getting frustrating as I want to be smooth enough to get racing online.

Try increasing the Analogue steer smooth option

Quote from Flame CZE :

Try increasing the Analogue steer smooth option

Tried that still no joy

Set Wheel turn compensation to 1.00 in Options - Controls.
https://en.lfsmanual.net/wiki/Options/Controls#Wheel.2FJoystick
If the controller is slightly worn out then having a deadzone in the middle of the steering axis is also helpful. You may use XInputPlus program for that, because LFS does not have this setting.