Camera Not Connecting on Macbook Air 2011

I've tried everything in this forum and online but cannot get my camera to function. Trying to do Facetime and Zoom video calls but I can't switch on the camera? It's on my Macbook Air 2011 running on Yosemite 10.10.5.

Is the operating system too outdate? It won't let me update that , either?

thanks for any suggestions since I need the camera in this time of isolation.

thank you