What's Wrong With This 1997 Half Dollar ? Help

Most of the time you will be able to determine it with out a size by size comparison. They will be obvious. Look for the normal things. Like the distance from a device from a rim or note the bust size if it in close or far away from the motto or other letters on the edge of a coin. But the biggest clue is to use the same year of coin.

Next question: How to size two images? You need editing software for images. Crop the images to the same boundary. (Same devices, rims edges of bust/building edges) Then size them the same and move them together on one image.
Horizontal:

Vertical:

Foursquare:

Same pair of images with them rotated to show vertically and horizontally how they compare.

Note how all images were cropped the same and sized the same.
Comparisions:


These are handy when you want the image right next to each other to see the differences or the same thing going on with two/or more different coins/

If you can see the copper core on the edge, then it is almost certainly a genuine coin as no counterfeiter would use cupronickel clad metal stock.