Hi Da Margon….not quite sure if I understand your question, but are you referring to after installing the theme, it does not look like the demo website? If I understand this correctly, you have to setup your site based on your needs. The demo site and how things look is just for display and showing what the theme can do. This will be the same for most if not all themes from anywhere.
The part where you say widgets cannot be dragged and dropped into the positions, this sounds like your WordPress widgets editor is locked and does not allow you to drag widgets. If this is true, then when you are at the Widgets page in the admin, go to the top right corner and click on Screen Options and then click the text link “Disable Accessibility Mode”.