Pick up/borrow a headphone jack to rca cable, plug headphones into that. If you still get nothing, your line out may just plain not work.

Great screenshots - it isn't obvious how to switch the recording input and many don't realise that basic recording software can't do it for you.

It may be the laptop only has mic-in for a headset mic and no line-in at all (even though the sound chip might, but there's no socket for it) - or if you dig into every option you can find in the audio properties, maybe there's selection between mic or line for the single socket. Check the spec for the model you have.

In the end, you might have to get a basic USB soundcard - the quality wont be worse than the built in one.

Most mic inputs are mono. If you record stereo off it, you get 2 identical channels. It's only the tip of the mic jack that carries signal.

Jim