A folder "the_addon_name" --> containing always (and at least) an "__init__.py" file. The folder of a multifile addon is nearly always downloaded zipped. Go to preferences, addons, click on "install..
This blender addon will import motion from mmd's .vmd file onto Daz or CC models, with or without mmd model. Install the .zip file you get from online shop. Search "Vmd retargeting" in your addon list ...