When Google is not working on your iPhone/iPad, the first thing you should check is your cellular data. Ensure that the connection is intact or the Wi-Fi is appropriately connected.
Another reason Google is not working on iPhone/iPad is that your cache memory is full. Visiting a lot of websites on your browser can fill up your cache memory very quickly.
A quick solution to get rid of accumulated memory cache would be to clear your browser cache. Go to your history, check the boxes next to Cookies, Site Data, Cache Images, and Files, then tap Clear browsing data. (You will find more steps to clear cache memory below.)
Also, if you are using an outdated browser, Google will not work on your iPhone/iPad. More steps to update your browser and address other issues causing Google not to work on iPhone will be discussed by me later.