If you have a new computer, you would want to first install the game via Steam. You should not being installing from a copy.
If you have any mods, I would recommend redownloading them and installing them fresh. That way you don't have any issues copying from a previous version of 7D2D.
You actually would transfer over two folders - that one mentioned above for the worlds and the second is the Save Games folder. However, if you are missing the GeneratedWorlds folder, it might be best just to restart the game a fresh. Generate a new map and start over.
I got a similar situation that will occur this week. For my new computer, I bought a second SSD to install and plan on installing my games onto it. When I do that, I plan on just doing a clean Steam install and install all the games I am playing now, along with any mods I want to bring over.