I believe when I clicked on a link, my Safari became infected with a virus

susiefromel paso wrote:

I don’t know how to do that with my iPad….?

For iPad, you will have to quit the app using the App Switcher, then open it again.

Quit and reopen an app on iPad - Apple Support

The way to access the App Switcher on an iPad without a Home button is done by swiping half way up from the bottom of the screen, and navigate to the Safari app. When you find it, then swipe up on it.

Please read Phony "tech support" / "ransomware" popups and web pages - Apple Community.

Dire "Infected" / "Locked" / "Virus" / "Damaged" / etc are all scams intended to deceive and frighten you into taking inappropriate actions. They are just various odors of the same putrid garbage.

The above User Tip describes what to do about them.

Quit Safari and hold down the Shift key and start Safari again. It should be gone.

“Blue screen warning”?

Please explain.

If you are still seeing a bogus message, you should be able to close the offending Safari page/tab.