Spawning from two different points with text

I want to spawn the obstacle exactly as per the below link.



I want exactly the same functionality of spawning obstacles with numbering.
Two problems I faced:
1. I tried with two prefabs i.e. right/left with right Z position is 90 and left Z position is 60. But in this case in 02 seconds already 2 to 3 right obstacles shown on screen then left one will show
2. Unable to add increasing number functionality.

Anyone please guide me.