sorry im a noob...ok so i downloaded an autox lyt and i put it in layouts...so how do i get it on the game though?

load the right track, Shift + U, "Load Layout"

And some detailed info: http://en.lfsmanual.net/wiki/Autocross

so i gotta dowload the editor thingy then?

No - its built in! Just press Shift + U!

ok i am...its not working...

It is working. You are doing something wrong.

1) Start a singleplayer game with the corresponding track
2) Join
3) Press SHIFT+U
4) Press "Load layout" and select the right one
5) Press "Set as default" and then "exit"