How to set player as 3d model

how do i set this model as player
and how do i make it so that the gun next to it is in its hands all times107136-capture.png

Add Character Controller component to the model ans assign the camera to it as a child.
Then add the gun to the hand/handbone as a child.

Later, you will change guns by using this command per script: Unity - Scripting API: Transform.SetParent