What's wrong with this camera, please?

Could be a circuit needs replacement - take it to a digital camera repair place for a better opinion from an expert.

You have an older 5mp camera. Im sure it gave you excellent photos.

I dont think its worth taking in for professional camera. You can now get better cameras for 65-100 pounds. ($100-$150 US). You will likely have to pay for the estimate whether or not you decide to repair it. I would opt for a new camera. Digital point n shoots once past warranty period are really disposable cameras unless its a repair you can perform yourself.

Looks like a sensor fault to me. May not be worth repairing.

Looks like a magenta color shift. Could be a sensor problem. Your question is for a qualified technician.

Go into your settings menu and reset everything to the default.