You can see your MySQL details, including MySQL hostname, by accessing your hPanel and locating the MySQL Databases menu in the Databases section.
The MySQL Host section at the bottom of the page represents your MySQL hostname :)
NOTES:
- If your List of Current MySQL Databases and Users section is empty, you need to create a MySQL Database first.
- If you wish to connect to your MySQL database remotely, you can check how to set up a remote MySQL access.