To copy a region, make sure you are in object mouse mode. Move the mouse pointer into the region Left-click and drag. A new region is created and will follow the mouse pointer as it moves. See "moving Regions" for more details on moving the copied region around.
To copy multiple regions, select them before copying. Then click+drag on one of the selected regions. All the regions will be copied and as they move, the will keep their positions relative to each other.
If you want to copy region(s) to other track(s) but keep the copies at the exact position on the timeline as the originals, simply use Middle-click-drag instead.