Hello creators
How do I code the background
So that it is repeated without extending it ?? 
Well, you can use the Tilemap object and extend it, that will repeat the background without any changes to the sprite size
Sorry, I couldn’t quite understand what you meant.
Is it infinite going game?
If yes then you can keep that road thing as a tiled map in another layer and only change the x position of camera to focus.x
You can change the offset of the tiled object on the axis you want to have the effect of moving (If I am remembering correctly, there is an action for that) You can hook it to the player speed or something else and experiment with the values a bit to get a perfect result
: )