Hi Marjorie__,
Welcome to Apple Support Communities. First, it may be best to isolate this to just FaceTime or your iPhone camera. Try these steps from If the camera or flash on your iPhone, iPad, or iPod touch isn't working - Apple Support to see where the issue occurs.
Remove case, accessory, or film and test
1. Remove any case, accessory, or film that might block the camera or flash or that places a magnet near the camera.
2. Test the camera by trying to take a photo.
If you find that the issue only occurs with FaceTime, use the guidance from If you can't make or receive a FaceTime call on your iPhone or iPad - Apple Support to proceed. All steps there can help, but in particular, testing on another network will help isolate as well as these steps from the bottom section.
1. Make sure that your device has a Wi-Fi connection to the internet or a cellular-data connection.
Learn more if you're using router, firewall, or security software that restricts internet access.
2. If you're trying to use FaceTime over cellular, make sure that Use Cellular Data is on for FaceTime. Go to Settings and tap Cellular or tap Mobile Data, then turn on FaceTime. If you're using an iPad, you might see Settings > Cellular Data.
3. Go to Settings > FaceTime and make sure that FaceTime is on.
• If you see "Waiting for Activation," turn FaceTime off and then on again. Learn what to do if you can't activate FaceTime.
• If you don't see the FaceTime setting, make sure that Camera and FaceTime aren't off in Settings > Screen Time > Content & Privacy Restrictions > Allowed Apps.
• Make sure that you have the correct phone number or email address listed.
4. Go to Settings > General > Date & Time and turn on Set Automatically.
5. Restart your device.
6. Update your device to the latest version of iOS or iPadOS.
Best of luck.