To have a copy of a project can be really useful if you want to experiment with settings and skins but are afraid of destroying your project when doing so. In this way you can experiment with the skins and settings and when you find something you like you can safely add it to the real project.
You will probably find the project in the folder on your computer called My Albums. But in this example I'm using the Sample portfolio which is not stored in My Albums. I can see where the project is stored by looking at the path shown in the explore view.
This is another project on my computer which is stored in the My albums folder. This is probably how your path will look like.
When you have found the project in your file system it's time to make a copy of it.
Right click the folder and click Copy "Album title". Or you can mark the folder and press ctrl+C.
Then right click anywhere and click Paste Item. Or press ctrl + V.
The copy of the project folder will probably get a default name like in this case, Sample Portfolio Copy. The project will get the same name as the folder so you can rename the folder if you want the project to have another Title.
Open the Empty project in jalbum and drag and drop the copied project folder to jalbum and the new copy of the project will open.