how do you add free models from the internet to your work?

so i just downloaded some free models from the internet,but i dont know how to paste them into my game?!? can someone help me please?

Put the model in your project’s assets-folder. You can either do this manually through copying it to the folder, dragging and dropping the model from the folder to the Project view or right-clicking the Project view and choose “Import New Asset…”.

Read more about the Asset Workflow and the How to.

The supported formats at the time being are:

Maya .mb & .ma1				
3D Studio Max .max1				
Cheetah 3D .jas1				
Cinema 4D .c4d1 3				
Blender .blend1				
modo .lxo2				
Autodesk FBX				
COLLADA				
Carrara1				
Lightwave1				
XSI 5.x1				
SketchUp Pro1				
Wings 3D1				
3D Studio .3ds				
Wavefront .obj				
Drawing Interchange Files .dxf