Right-click on an empty area of the website or choose an element, and click on Inspect. Alternatively, you can use the keyboard shortcut Ctrl+Shift+I, which will open all the development tools. You can check the Elements tab to inspect elements or the Console tab to detect any errors or warnings.

If you have Chrome as your default browser, you can just double-click the HTML file and it opens in Chrome. If you try this and your computer doesn't recognize your file, the system prompts you to open it using one of the previously installed apps or to search the extension on the internet.