I have these red outlines around objects which I believe are to show what is in focus but I'd like to know how to turn this off and on. I don't like how it's on constantly. Where do I go to shut this off?

Can you post a screen shot.

Assume we're talking GO app. it's a focus aid.

Go to General settings, (top right on your screen).

Choose Peak Focus threshold. Set it to "None"

Yes, sorry I didn't fully understand your question.
As the prior person posted, those are the instructions, you can go 70,80,90%, or none.Here's an explanation from another user.

Focus peaking is an advanced feature that helps obtain sharper focus. It is by default 'off' (the reason for this should be self evident after you use the feature a little) To activate it: Go to 'General Settings' where you will find 'Focus Peaking' - 'None' Scroll this to '90%' if there is subject has very high contrast borders e.g. a building set in the background of clear sky and lower if the separation in contrast between the edges of interest and the background is murkier. Think of this as a threshold control that raises or lowers the criterion of the focus detector. You will need to be in Manual Focus mode AND in Photo (not video) mode  to activate the feature When the feature is on, you'll see red lines outlining the edge(s) of the subject if you are in focus but not when you are out of it. So the more red edges you see, the sharper your focus; adjust until focus 'peaks'

Thank you very much.