No camera device found

I would attempt to reset the SMC.

If that doesn't work, unfortunately there is no Apple Store available. It is more cost effective to get an external camera.

An older laptop like that is worth only about $350 on the open market, and the screen is about $100 alone on the open market, and you take your chances the problem isn't something wrong with the logicboard itself.

MacPro is a desktop machine. MacBook Pro is a notebook machine. If indeed you have a MacPro, there is no camera built-in. You'll want a camera like the Logitech c615 which is a clip on camera that connects via USB, or a Display with a built-in camera that connects via HDMI or Thunderbolt.

If you are talking the MacBook Pro on your signature, reasons it may not see the camera are if another camera is connected, if a logicboard repair was done, or if the cable into the display got damaged.

Facetime may not see the camera, if you are connected behind an office network firewall that blocks those ports.

Tethering over a cell phone may not give you sufficient bandwidth to do Facetime conversations.

Use Photobooth in your applications folder with no other programs open to verify it is not the camera itself that is having an issue.