Safari "Preferences" and other menu items are greyed out

Also try setting up another admin user account to see if the same problem continues.

Isolating an issue by using another user account 

If it works in the Safe Mode, try running this program when booted normally and then copy and paste the output in a reply. The program was created by Etresoft, a frequent contributor.  Please use copy and paste as screen shots can be hard to read. Click “Share Report” button in the toolbar, select “Copy to Clipboard” and then paste into a reply. This will show what is running on your computer. No personal information is shown. If the log won’t post, try posting it in Pastebin and provide a link in a reply        Pastebin

Etrecheck – System Information

Safari/Preferences/Advanced - enable the Develop menu, then go there and Empty Caches. Quit/reopen Safari and test. Then try Safari/History/Show History and delete all history items.  Quit/reopen Safari and test. You can also try try Safari/Clear History…. The down side is it clears all cookies. Doing this may cause some sites to no longer recognize your computer as one that has visited the web site. Go to Finder and select your user/home folder. With that Finder window as the front window, either select Finder/View/Show View options or go command - J.  When the View options opens, check ’Show Library Folder’. That should make your user library folder visible in your user/home folder.  Select Library/Caches/com.apple.Safari/Cache.db and move it to the trash.

Go to Safari Preferences/Extensions and turn all extensions off. Quit/reopen Safari and test. If okay, turn the extensions on one by one until you figure out what extension is causing the problem.

 Safari Corruption       See post by Linc Davis

Startup in Safe Mode and see if it works as expected:

Use safe mode to isolate issues with your Mac - Apple Support

Backup your Mac.

Reinstall macOS from macOS recovery.

How to reinstall macOS from macOS Recovery - Apple Support

No you should not delete any files from user library > containers .

If safari is corrupted , click on finder > take cursor on top menu bar > hold option key then drag and drop safari folder to the desktop , also delete the complete contents of caches , cookies , saved application state into the trash , then restart the Mac .

In your case the safari preferences are greyed out , try the above method all the contents and safari folder will be recreated .

If in any case this doesn't work contact apple support senior care apple advisor see this link https://support.apple.com/en-in/HT201232

I don't see anything I recognize as normally causing problems. Try quitting all open applications to include the Banjo istats, quit/reopen Safari and test.

Creating a new test user account is not working , even you enter in user library > drag and drop the complete folder safari to the desktop or find a folder preferences > delete com.apple.safari.plist and again reset the home page I doubt it will work , the system files are corrupted erase the hard drive and reinstall Mac OS see this article https://support.apple.com/en-in/HT204904

Try moving them to your Desktop, restart the computer, and test. If no difference, return the files to where you got them.

You may  have adware/malware installed. Try downloading this program which was written by Thomas R, a long time poster. The program will search for malware/adware The program will do the work for you which makes it easy. It may be necessary to run more than one scan. After running the scans, restart the computer.

Malwarebytes Anti-Malware for Mac      10.10 and later

Malwarebytes uninstall

It may not help, but try running/posting the Etrecheck report.