Question

how to make a Ushape bridge from paper or anything

Answer 1

draw the bridge with some pencil or marker
and then cut it with a cutter or scissors

Answer 2

You can make a u shape bridge like this.
First : draw a u shape in the cardboard and then cut it.
Second : Then take a cardboard and cut four rectangles.
Third : Then paste 4 rectangles on the four corner 
Then your  U shape bridge is ready.