Safari crashed. How to fix it?

Go step by step and test.

1. Quit Safari, launch Safari holding the Shift key down.

    https://support.apple.com/en-us/HT203987

2. Startup in Safe Mode

https://support.apple.com/guide/mac-help/start-up-your-mac-in-safe-mode-mh21245/mac.  

    Quote:

    It also does a basic check of your startup disk, similar to using First Aid in Disk Utility. 

    And it deletes some system caches, including font caches and 

  the kernel cache, which are automatically created again as needed

.

3. Clear History

    https://support.apple.com/guide/safari/clear-your-browsing-history-sfri47acf5d6/mac

    Please read the article before clearing history, 

    this is like a low level resetting of Safari without affecting passwords and bookmarks.

4. If Safari doesn't open a webpage or isn’t working as expected

    https://support.apple.com/en-us/HT204098

5 For additional troubleshooting steps::

  https://support.apple.com/guide/mac-help/if-an-app-freezes-or-quits-unexpectedly-mchlp257