Years ago, I had made multiple WP sites and now I see some of them as WP folders on my local disk. I want to make them as working websites. How can I do that?
Your database contains all your data for each of your sites. Without the databases, your sites will not have any posts, pages, site configuration, users, comments, or settings. If you stand these back up, you will have to create blank databases for each and install WordPress from scratch.
You can follow the "Famous 5-minute Installation" to get started quickly.