Welcome to the forums @watermeloncandy
Power Duplicate (CTRL+J) should work but it may not work if you have de-selected your layer before re-selecting and then duplicating. (The power part of the duplicate functionality is lost when your layer is deselected.)
Another technique to use for distributing layers is to use the Align & Distribute functionality, see attached video where I duplicate one line in place and then distribute.
There will probably be other/better ways to do this so keep popping back to see other suggestions.