Copying a region is done using the Grab mouse mode, by moving the mouse pointer into the region and left-dragging. Ardour creates a new region and follows the mouse pointer as it moves. See Move Regions for more details on moving the copied region.
Copying multiple regions requires them to be selected before copying. Then left-dragging one of the selected regions will copy the regions as they move. The copied regions will keep their positions relative to each other.
Copying region(s) to other track(s) while keeping the copies at the same exact position on the timeline as the originals is done by simply using a Middle-drag instead.