To login to your web hosting control panel, go to the url: [your_website.com]/cpanel, enter in your domain name for the [your_website.com] part.
You may get some kind of Security Certificate Error, such as:
Click on the "Continue to this website" link, to proceed to the login page:
Here, login to your web hosting account using your provided username/password. (You can change your provided password from your web hosting account if you would like.) And click "Log in".