A polarizing filter works sort of like a grid, a grid that only allows light from one direction to pass through it. You may not know this but most polarizing filters can be rotated. Hold your filter up in front of your face and rotate it. Do that while looking at anything with scattered light, like say a reflection in a window. You will see that the filter (at a certain rotation) will eliminate all scattered light sources.
This will reduce reflections or haze on the horizon. Do note that if you’re shooting in an environment that has naturally scattered light, say a cloudy day, the polarizing filter won’t help too much. They work best with direct light sources, like the sun.
You will notice just how much bluer skies become and how much more contrast your images will have.
Here is an example of reflections specifically:
photo by aidanwojtas
In your case the skies are very nice and the clouds look great!
Of course in a photography like this you may want to actually avoid a polarizer because the can kill your reflections… In this case the reflections are quite nice… Anyway, to each her own…
I’m glad you got your hands on a filter.
I encourage you to play around with it. Rotate it on your camera if yours has that ability and take note of the difference you see in the image.