Hi,
I bought front license plate bracket for my son's Camry XLE,and the holes for the plate are not only too big,but they have depth,requiring a way longer screw. There is also no threaded catch for a normal screw. What hardware is supposed to be used with it?

 

Try using a rib screw insert/wall screw insert for walls.

There are threaded inserts that push into the hole then can be expanded to hold it in place.