You can turn off 'personalization', which affects ads supplied by Google across millions of websites
https://adssettings.google.com/anonymous
but you can't get rid of the ads which appear at the top of Google search results. Those advertisers pay Google megabucks to make sure that those ads appear there and Google isn't going to risk revenue by offering any way to block them.
There are, of course, lots of other search engines that you can use instead though. DuckDuckGo has fewer ads and doesn't use web-tracking:
https://duckduckgo.com/