You can find the database information by looking at your wp-config.php (which will be in your WordPress root folder).
Your wp-config.php will probably tell you then that your database host is “localhost” (DB_HOST) and since you are using XAMPP locally, the location of your DB would be wherever you are running MySQL basis your XAMPP installation. XAMPP comes with phpMyAdmin for managing the DB. That should help.
wp-config.php will also tell you the name of your database (DB_NAME). The table prefix is found farther down where it says $table_prefix.