what is the green dot at the top of my screen

It indicates that your camera is in use.

Orange indicates that the microphone is in use.

It means an app is using your camera..it’s literally scaring me

I thought the red dot was for the microphone?

There seems to be some confusion on that one. Apple’s documentation states Orange for microphone, Green for camera. However, several folks are reporting a red indicator when using the microphone.