Bubble Shooter replica with some extra features

Hello everyone I decided to create a Bubble Shooter replica with some extra features, I’ve already created all sprites, the arrow’s movement and basic look.
This is how it looks


I dont know how and where initalize 100 spheres in random places in the background.
I think there should be an array of these sprites, or maybe I’m wrong.
Every tips welcome.

take a look at busta move, on youtube, this should give you a ruff idea, on the level creation, do a single level first using the editor unless you going to use a map editor, and go from there.