Resetting admin user details
You can't easily manually insert a user record. The password is not an MD5 hash, it a salted SHA-256 hash.

You hopefully made a backup, you should restore that. From there, you should consider to use drush, which is the by-far easiest way to log in, with drush uli to generate a one-time login link or drush upwd, to set the password of a user.