I want to have multiple image sprites come from the location that the barrel sprite comes from but have a random selection using a list. How would I make it that the spite that moves across the screen is random between multiple images/sprites?
You will need to keep a global list of the component blocks for those Sprites you want to move randomly.
You might need to keep two lists, one for active (visible and moving) sprites, and the other for those held in reserve, like bullets still in the gun.
There is a select random item from list block you can use to pick the next bullet.
Look in the Any Sprites section of the Blocks Editor pallette for generic blocks and use the Select List Item block to get specific sprite components to feed the generic (any Sprite) blocks.