HI Trialg
Welcome 
There’s no silly questions,. just simple answers 
With the item selected, go to Edit /Copy.
Jump back into the scene,.. Assembly room.
Go to Insert, Vertex object,. and once you’re in there,. Edit / Paste.
The object you copied will be pasted into the same position as it was when you copied it.
but it’s now a completely separate model.
Another method is to use the option in the Assembly room to Edit / Split object,. which will take a multi poly-mesh object and create an object from each separate poly-mesh.
this isn’t always the most ideal solution if you want to just work one one part of a model in the vertex modeller, you can select and Hide the parts you don’t want to work on, and then make them visible again, when you’re done.
Hope that makes sense 