sharing ms office docs does this mean i should have anti-virus

macOS already has great built-in security especially when combined with the user also practicing safe computing habits as outlined in this excellent article written by a respected forum contributor (even applies equally well to Windows users):

Effective defenses against malware and other threats - Apple Community

Anti-virus apps, cleaning/optimizer apps, and third party security software all interfere with the normal operation of macOS (of any OS) at a very low level, so these types of apps usually cause more problems than they solve. Many of these types of apps are also collecting & selling your personal information and many also have had security vulnerabilities themselves which actually makes your system much less secure.