ftp/filezilla

My site was up and running, but I attempted to make some changes within ftp and am getting a database error. Essentially, to the best of my ability I reconfigured the wp-config-sample.php file, saving it as wp-config.php, and it is in my public_html file on the remote server. Not sure what I’ve done to throw it off. Is it supposed to be elsewhere than /public_html? I still have the wp-config-sample.php, but I was making changes – adding the codes from that key page – one by one, so the wp-config-sample.php, in the same file, is a replica of the config.php I created.
Thanks for any help!