How can I create a Google account without it being saved to my device?
Sure you can do that. You have to switch to incognito browsing on your browser.

Every browser has incognito. On Opera mini, it is called private browsing.

For Chrome, click on the three horizontal lines at the right-top side of the browser and select new incognito tab.

On Opera, you can switch to private browsing by clicking on the tabs icon then select Private.

I hope this helps.