To see your start page, open a new window or tab in Safari 14 or later.
To customize your start page, click the customizations button 
in the lower-right corner. Then choose from these options:
Favorites shows the pages bookmarked as favorites. If you drag a favorite to another position, or drag it out of the window to delete it, your Favorites Bar shows the changes as well.
Frequently Visited shows the websites you visited frequently throughout the day. You can drag items out of the window to remove them individually, or clear your browsing history to remove all items.
Privacy Report shows how Safari has protected your browsing across all the websites you've visited. Click the report for more detail.
Siri Suggestions shows a list of suggested websites that may interest you.
Reading List shows the pages you saved to read later.
iCloud Tabs helps you navigate to open tabs on your other devices. Move your pointer over this section to reveal a menu 
of your other devices and a button to show more tabs, if available.
Background Image offers a curated gallery of images to choose from, and the option to add your own. Scroll right to see more, or click the add button (+) to choose your own image.
If you don't see a start page, choose Safari > Preferences, click General, then make sure that the ”New windows open with” or ”New tabs open with” menu is set to Start Page.