Electrical – Electric stove wiring

Odd that you said you had a white wire that was hot. Both white wires should be neutral and have no voltage. Seems to me wires would go like this: connect all black wires together. That will run hot all the time to the fan as well as sending power downstream. Next tie all white wires together. That will provide neutral to the fan as well as pass neutral downstream. Ideally there would be a bare copper wire coming from the hot side and another to continue downstream. The red to blue should switch the light, providing that blue is the correct one for the light.

There is no way to tell what to connect to. It depends on how they wired it. I think it is safe to assume you should connect to the single black since it is in that box by itself like that. And yes, you would connect to the white and green with the other two wires. The instructions are not sparse, they show what you need to connect to. They do not know or care how your house is wired, nor should they. I will say, that box for the porch light is NOT appropriate. That is a collar box meant to mount onto an existing flush box. The wood of the logs is exposed to the back side of the box.

I also see a hole in the back of that collar box. Is this new light meant to be inside or out? If outside you'll need to replace that existing Wiremold collar box with a regular box, then run a cable from the back of the box into the back of a flush box outside.