How to get rid of a virus

No, you don’t. There are no known viruses that can affect a non-jailbroken.

If you are getting calendar entries saying you do see here: link-> Delete spam calendars and events on iPhone - Apple Support

If you are seeing messages on a browser, you can ignore them.

No you don't.

Any pop up from a website is a scam designed to scare you into downloading useless software.

Install an ad blocker to stop seeing such ads.

Forgot about the calendar spam.

Thanks for reminding me.