There are a number of ways you can duplicate elements in Figma:
1. Select the element and use the Command + D shortcut. This will duplicate the element directly on top of the original. You can then click + drag to move the duplicate elsewhere on the canvas.
2. You can select the element and use the Option + click and drag to drag out a duplicate. When using this method, we show the redline distances from neighboring shapes.
3. You can also use the basic Copy + Paste functionality (Command C and Command V, respectively on macOS)