Answer:
I come with a train and go with a train and the train doesn't need me but can't go without me.
I am the beginning of eternity the end of time and space the beginning of every end the end of every place.
I go up and down at the same time. Up towards to sky and down towards the ground
I let water fall on you while everyone else stays dry. What am I?
I am constantly overlooked by everyone but everyone has me.
What language does a billboard speak?