Screenshots are not taken by the camera. You can swipe the edge of your hand across the screen to take the screen shot, pull down the quick panel and select "take screenshot". If the button is not there, you need to edit your quick panel to add it.
Go to your settings and make sure that your side button settings are for what you wanted. If you want to take pictures using the side button, you need to make sure the double press action is turned on, and that the action is set to quick launch the camera. Settings/advanced features/side button.
Why does everyone who knows nothing about their phone settings jump to the conclusion that if they can't do something, their phone is hacked? Unless you have credible reason to believe you've been hacked, you shouldn't claim it.
