1.1 - On the file downloaded from https://themeforest.net/ , it have a file called 'DEMO DATA'.
1.2 - You need to go DEMO DATA > Choose the Home layout you want > Open file > Copy all data
You can use the Sublime Text to open file
2.1 - Go to Customize > Theme actions > Edit code
2.2 - Open "setting_data.json" file > Paste all the data which copied from ''DEMO DATA' to here > click to 'SAVE'
Just support import config sections the same on demo, NOT support import images, products, data the same on demo.
You should watch this tutorial video to know more: https://www.youtube.com/watch?v=sUDh0V_HMMs&list=PLZSqbv2i8LOBCosw-vNCjyhmJ5BmrmCqA&index=2