Unwanted 'favourites' page as homepage in Safari on 2015 iMac running Monterey

2015 21.5" iMac running Monterey 12.7.6.

Until a recent upgrade I used to use Google Search as my default opening page, and have set my homepage in Safari Preferences as https://www.google.com/

No matter what I do my opening page is a very annoying page of icons described as 'favourites'. They are not my favourites and there are too many of them for me to delete individually. Can anyone advise me what to do?

And now I can't remove macOS Sonoma as my topic, even though it isn't my topic!!

[Re-Titled by Moderator]

Original Title: Can't set the start page I want; I enter it in Safari Preferences but an unwanted page of 'favourites' keeps coming up as Homepage.