Most of the options that you are (not) seeing is because Wappler has developed tremendously (a Trump expression ) in the past couple of years.
If you want to experiment with Wappler, follow this easy to understand tutorial. It contains more features than what you are looking for, or are used to. But it will get you up to speed.
Duplicate button has been removed a while back, in order to simplify the selection in design view.
You can just use Ctrl+D keys combination, or use the duplicate button in App Structure.