Never use any anti-virus software because they have a long history of interfering with the operating system and applications. The operating system itself is on a read-only, code-signed volume that malware simply cannot be installed into. Any virus/malware written for Windows will not execute on the Mac.
Yes, there is adware/malware that can get installed into non-System areas of the Mac, but these are usually not found or prevented by anti-virus software, and most commonly are introduced by the user themselves by deliberately downloading software from non-vendor sites, or by inadvertently clicking buttons in email or websites where they shouldn't. For this type of software, there is Malwarebytes which is free, or by subscription. For the first few years of its availability, Malwarebytes was not advertised, or mentioned on their website as an anti-virus tool. Now it is. Probably marketing to compete with all of the other A/V products out there. Once installed, it can also be removed from a menu item on its Help menu. Though I have used it in the past, I don't use it now.
Whether you know it or not, macOS is a UNIX operating system beneath the Finder and that further protects it from infections. Unlike Microsoft, Apple has taken operating system security much farther and there is a white-paper about what they have done to protect the operating system and user from malware invasion.
The following will discuss how Apple has taken steps to protect you and the Mac:
Apple Platform Security - Apple Support