"show sidebar" button is not clickable in Ventura .

How about trying the keyboard shortcut. Control + Command + S. Does that work? If not, reboot into safemode that will automatically run system diagnostics and repair things it finds broken or incorrect. Then boot back in regular mode and try it again.

Start up your Mac in safe mode - Apple Support

Try this as a last resort:

Open Finder, click Go menu and then 'Go to folder', navigate to /Users/Your_User_Name/Library/Preferences

Delete the file: com.apple.finder.plist

Reboot, then try again.