Are you doing this on local computer or on a domain? Please post link if it’s on a web host and I can take a look at it. Also ask your web hosting provider if they do backups. You might be able to recover from an earlier setup if they do.
If your website is new, I would recommend doing a clean install and recreating the whole thing again. I have done this and realized it’s faster to do it this way than try to fix something. But that’s only if you don’t have a lot of blog posts and data already on the site.
Some things I would recommend to do are:
1. Create a local wordpress install and test out your changes there. There are many youtube videos on this.
2. If using local install, FTP or use git push if your web host supports it, to push the files to your account.
2. Install and activate a wordpress backup plugin like UpDraftPlus which backups wordpress if your web hosting provider does not do backups. I would also recommend testing the backups it created after making some minor changes on your site so that if you ever need to recover from a backup, you would know that it works. Using the plugin I mentioned, you can backup on dropbox or google account. dropbox is free upto certain limit.
At the very least, do a backup of site so that you can recover if needed in the future.
