What is the difference between URL Targeting rules in Visual Editor Changes and Attribute targeting? Which one is the one where my experiment will be visible?

All targeting rules must match for an experiment to be active. In your example, since the attribute targeting is more specific, the URL targeting will basically be ignored. Attributes are fully custom and just do basic string comparisons. They aren't really meant to handle the complexities of URL matching (querystrings missing or out of order, etc.) If you're mostly using the visual editor, I recommend getting rid of the URL attribute entirely and just use the built in URL targeting instead.