There are 2 common locations where you can find your sites error logs and one common tool in your browser that can also assist troubleshoot your site
Websites Error Log
Once you are logged into your cPanel account, access the File Manager Tool
Navigate to your websites folder, this is the public_html folder by default.
In this folder you will see the Error_log file.
Right clicking on the file and clicking on View option will enable you to see the logs.
Server Error Log
You can find the server error logs in the Metrics area using the Errors tool.
Browser Troubleshooting Options
Within your browser right click on the page and Select the Inspect Tool
Depending on your browser you should see all error messages display in the Bottom or Top Right hand side.