How to use asset bundels (Read More)

So I have been working on an fps game and the build has been getting quite large in size. So I thought of using AssetBundels, I have managed to put my environments as individual prefabs and asset bundle groups.

My question is how do I get it to load the prefab from the group? And also how do I check if the group has been downloaded.

This is how I'm planning for the folder structure to be