You will only be seeing Unassigned when you restrict the File path category to a folder on your system (the default Files view has no path set, which means essentially the root of the folder tree on your Windows system). All files that MC has in its database that do not start with this folder location will be placed into the Unassigned category. So you can either blank out the folder path to use MC's default File view settings, or narrow the view's scope by configuring the view's Set rules for file display..., adding a Rule: Filename (path) starts with <same path selected in File path category>. This probably isn't what you want, as MC uses the location field for more than just paths, and it might be worth using the default rule for now.
If you want File Type to be the first category, customize the view again, and move the File Type category up one.