Windows Defender, ignore the baseline scores in AV Testing reports, what do you think about this for basic Antivirus protection?
Remember,
Windows 10 has increased it's Windows Defender protection capabilities, than compared to all previous versions.
Real-time Protection: Windows Defender & Firewall
Browser Protection: HitmanPro Alert, Bitdefender Trafficlight
On-demand: HitmanPro, Malwarebytes Anti-Malware Free
Optional: Unchecky (prevents the installation of bundleware; adware and other potentially unwanted software)
Consider the above before bogging down your system with unnecessary Free Antivirus software by other vendors. Some cause more issues that what it's actually worth, for example, many Free Antivirus are limited, or promote their paid versions through notifications or messages centres.