9. To see your new web page, double-click on the HTML file. It'll open in your default web browser. Here's the web page being viewed in Firefox. The HTML file only contains the text “HTML stuff would be in here”.
11. To edit the CSS file, just double-click to open it with your default plain text editor (like Notepad). To edit the HTML file, right-click it and go to Open With > Notepad (or whatever editor you use).