I don’t remember what was my passcode
I don’t remember what the passcode was on my iPhone, what to I do getting a virus message
iPhone 11, iOS 14
If you've forgotten the passcode to your iPhone,, you will need to connect your device to a computer or Macbook running iTunes. You will lose any data that isn't backed up to iCloud or iTunes.
Follow the Steps at - If you’ve forgotten your iPhone passcode – Apple Support (UK)
The "iPhone virus message" sounds like it could be a scam, do not click on this message and close down the webpage from which it came from.
Recognise and avoid phishing messages, phony support calls and other scams – Apple Support