The sprite would spawn, move towards the sprite the player is controlling, and a set time after it spawns, a duplicate would spawn out of the same place the original did. No clue how to do this.
You probably want a coroutine to spawn the sprites periodically, look at this video of the Space Shooter tutorial for a reference: Boundaries, Hazards and Enemies - Unity Learn
If you’re trying to make your own game and didn’t follow any of the official tutorial I suggest you do that entire tutorial. It’s outdated, but you can learn a lot from it anyway, just ignore the “displaying the score” class (the GUI system used was replaced) and note that some code might be invalid in Unity 5 (it’s easy to fix them).
To make the sprites follow the player sprite look here: How to create a basic follow AI - Unity Answers