Summarize the following:
In general, this is near the URL text box and either looks like a small tab or has a plus sign, but the exact appearance will depend on your browser. In Chrome, it resembles a blank box, and in Safari and Firefox it has a plus sign on it. You'll see a blank page.  You'll see the desired page load up.

Summary:
Look for the "add new tab" icon at the top of your browser. Click the button. Enter the URL of the page you want to see in the address bar. Click ↵ Enter (Windows) or ⏎ Return (Mac).