@OnlyOneLab You need to copy them in the Content’s root folder
Delete whatever you copied
Copy over the files again to the Content/ folder
If you need this in a sub folder, the from within the editor’s content browser, move the files to a sub folder so UnrealEd can properly move them
Add starter content to the project
Also refer the quick start guide instructions for each map. There are some art dependencies for some maps (like infinity blade’s free assets from the marketplace) that you need to add to you project first