Virus’s in my phone

You got tricked into installing a rogue calendar; your phone does not have a virus.

If your phone has iOS 13 or earlier: Go to Settings/Passwords & Accounts, look under Subscribed Calendars, tap on the offending calendar and delete it.

If your phone has iOS 14: Go to Settings/Calendar/Accounts, look under Subscribed Calendars, tap on the offending calendar and delete it.

And in the future be wary of “free” offers.

Calendar spam and not a virus.

Delete the rogue calendar.

You installed calendar spam. Go into Settings and locate any active calendars you don't recognize. Delete them.