Health Decrease

How can I make my FPS character lose health and when he loses health the screen will turn red on the sides to show he is hurt? Also how can he regenerate?

You can do this by adding a script containing relevant syntax and properly declared variables. You can achieve this like, Jessy said, by learning about Unity first! Also READ THE FAQ before posting any more questions.

Lol, as Jessy said, you need to actually learn how to code before you actually take up upon yourself to do this...

However, in general, you give the player a health, have it decrease when shot, then if it's less than 10, you start the whole screen red thing which can be rendered or w/e, then you have the health auto increase by one every second, and then have it so that if it's above 100, make it 100 again... Easy. Just learn how to code.