All WP themes freebies don’t work, because dont have stylesheet styles.css.
If you’re getting an error about “style.css” missing, then either:
You’re uploading the wrong file. Download files for freebies come with documentation and other files. You can’t upload this straight into WordPress. First, you need to extract it onto your computer and look for another .zip inside which can be uploaded into WordPress.
You downloaded a theme or template for a different platform (WordPress is just one of many CMS platforms), so it won’t be compatible.
The Help Center has a very nice article which goes into further detail, give it a read if you’re still having issues:
Let us know if you can’t figure it out!