No such thing as a dumb question... only dumb mistakes!!
The Tamron 18-250 will focus down to about 8.5" from the subject, and using it at 18mm the object is still pretty small.
Luckily, the minimum focus distance of 8.5" is the same throughout the zoom range, so by zooming in you can in effect, shoot a Macro or an image that takes up most of the field of view.
This is what a Macro is, an in focus shot that fills the screen or field fo view, so you have a high res image that you do not have to enlarge to see, losing the resolution in the process.
Phil