Hi, i couldn’t find the rig in your file. If you had a rig with bones then like character rig the head will be parented to the head bone the very top last bone. If you just want to join the head to shaft then in object mode select the shaft select the head and go to object>Join.
If you wanted the shaft to bend then use bendy bone setup.
If it’s of interest to you, Ctrl + P is parenting. Remember that the object last selected will become the parent, so select the armature last if you want to parent the head to the armature.
Ctrl + J is joining. This will make the head and shaft one mesh. I would prefer this method, but you do whatever’s easier.
I think you have directed the reply to the wrong person.
