Hello, kaltat27.
Welcome to Apple Support Communities.
From what I understand is that you're unable to give any of your apps permission to use the camera. I'd like to help. There are two reasons why this could be happening, either you'll need to reset the Location & Privacy settings or you have restrictions turned on. Here are some articles to help with this:
About privacy and Location Services in iOS 8 and later
"Reset or disable Location Services
Location warnings are the requests that apps (such as Camera, Compass, and Maps as well as location-based third-party apps) make to use Location Services with those apps. An app will ask for permission the first time it needs to access Location Services data. Tapping Allow will give that app permission to use Location Services as needed. Tapping Don't Allow will prevent an app from accessing Location Services data. Apps won't use your location until they have asked for your permission and you grant permission.
If you would like to reset all of your location settings to the factory default, go to Settings > General > Reset and tap Reset Location & Privacy. When your location and privacy settings are reset, apps will stop using your location until you grant them permission".
Use parental controls on your child's iPhone, iPad, and iPod touch
Let me know if this helps.
Cheers!