If you can’t open a Safari window on Mac
If you can’t open Safari or a new Safari window, try these suggestions.
Make sure you’re using the latest versions of Safari and macOS. To check for a Safari or macOS update, choose Apple menu
in the sidebar, then click Software Update on the right. (You may need to scroll down.) See Keep your Mac up to date.Check your startup disk for errors using Disk Utility.
If the other suggestions don’t help, try reinstalling macOS.
See alsoSafari Support website