i have idea for your problem, to know the progress you must compare the the player.X and the layout right edge , now using simple equation you can know the percentage of progress in the level , you can use this to make the bar and the background effects , how to make the background :
you have the layout width and , using the percentage from the level progress you can know the position of the sun,
for example if the you are in 20% of the level you know that the sun.X = 20% of the layout width.
this is the basic idea , you can extend it to make sun and moon , and for the background color just a sprite with different frames colors.