Here is a list of useful shortcuts you can use inside Youzign graphic editor.
Grouping objects together: hold Shift + click on at least two objects
Delete = Delete key (on Mac Fn+delete)
Duplicate = Ctrl + J
Undo = Ctrl + Z
Redo = Ctrl + Y
Nudge objects = Click on an object + ⬅️⬇️➡️⬆️ (keyboard arrows)
Move objects = Click on an object + Shift + ⬅️⬇️➡️⬆️ (keyboard arrows)