How Can I implement an object spawning system?

How would I go about making a system where different objects spawn I places(to be picked up and placed in an inventory). Kinda similar to where gear and guns and supplies spawn in survival games especially lilike apocalypse rising, deadmist, ect. Can someone explain a simpletter method of storing each value and making this system. You don't need to script the entire thing, just explain what kind of things I would need to do, and give some examples if you want

You have to first try to make it on your own.