If you have Windows 10 then the short answer is No.
Unlike older versions of windows purchasing antivirus software or installing a free version would have normally been my advice. Microsoft were at that time extremely poor at protecting their own operating system from attacks from malevolent agents.
That I now believe, has changed with the advent of Windows 10 coming to the market in 2015, over the years Windows Defender has gone from strength to strength.
Your choice though, but for the home user I don’t see any reason not to trust Windows Defender to protect you from Virus and Malware.
However, whether your choice is a third-party antivirus, or its native antivirus just make sure that you do the most important task, keep Windows 10 updated and all third-party apps updated as well, this will help to keep your operating system as healthy as possible.