how can I delete virus on my mac

There are no viruses on the Mac. Problem solved.

What symptoms are leading you to believe that you have one?

What makes you think you have a virus?

If you saw a scary pop-up message telling you that you've got a virus, and encouraging you to call a phone number for help, that's a scam. There isn't actually a virus. See:

Tech support scam pop-ups

(Fair disclosure: I am affiliated with Malwarebytes, whose site I am linking to above.)