Hello, Gwen_coco.
Thank you for using Apple Support Communities.
I understand you're having issues with the camera whenever opening apps that use it. I'd like to help. First make sure to disconnect any peripherals from the MacBook Pro. Then follow these two articles to reset the SMC and NVRAM:
How to reset the SMC of your Mac
Reset NVRAM or PRAM on your Mac
Then test to see if the issue persists. If it still does, create a test user account with Admin privileges: How to test an issue in another user account on your Mac
Moving forward the next after is going into safe mode:
How to use safe mode on your Mac
Keep me updated and provide the details of any error messages if you see any.
Best regards.