I think I may have just started to understand a tiny bit and have managed to change my ISO and get a few pictures I am happy with !
Getting better all the time, but room for improvement.
Looking at the EXIF data for DSC_8191 it says 1/1000s f/10 ISO6400. If you drop down to f/7.1 or f/8 your shutter speed will go up but it would be better to drop your ISO down even more which will help with reducing noise.
What is also noticeable is that you have blown Highlights because the image is overexposed. This means that there is no data at all in the whites. As Musoman says you could try changing to Spot Metering with would help but a better solution would be to enter the realms of Exposure Compensation or Exposure Bias or Exposure Value (EV) they're all the same thing with different names. This is the button to the right of your ISO button. You hold it down and rotate either the Front or Rear Dial ( probably the rear button, it is on mine) to override the camera's exposure determination, because it doesn't always get it right. You can override it in either 1/2 or 1/3 increments either + or -. In your case for this image you would need to drop it down to probably -0.7 or -1.0. What this effectively does by entering a minus compensation is that you would make the whole image darker by increasing the shutter speed to gather less light so consider it a bonus. It's not as confusing as it sounds. Focus on a fixed target and take a shot without compensation, then take the same shot (in the same lighting) with both Plus and Minus compensations and see for yourself the change in shutter speed and the effect on the image.
If you're struggling to grasp this let us know and we'll help you with it.
You can set your image review to display what's commonly know as "blinkies" these flash any areas of the image that are over exposed. Not sure on the D7200 how to do it so it's a case of RTFM I'm afraid.