Follow these steps.
Click the three lines from the top-right corner (the options button).
Click on Settings.
From there, just below the first setting, you should see three options from the “At start” headline.
Pick the last option, “Open a designated page or a set of pages” and click on “Set pages”.
Write “Google.com” in the window that will open. Or Google.fr, Google.de. Depending in which country you live.
Click ok and restart the browser.