Scam popups on MacBook Pro

New to both Apple/Macbook Pro and this forum. Looking to find an Antivirus for my Macbook Pro or if I even need to install one? My Chrome browser popped up an alert earlier that there may be a virus and when trying to check it McCafee Antivirus shows subscription is expired and I need to renew. So I'm not sure if I actually have a problem or if McCaffe wants me to sign up and its just a commercial I'm seeing. I heard a long time ago that the IOS system doesn't need antivirus, is that true or no? Thanks in advance for info of how to use the forum or the antivirus issue......Moorwhine

[Re-Titled by Moderator]