You can install an antivirus, but you really don’t need to. Malware for Linux is rare, and malware that targets desktop Linux users is extremely rare (to the point that it’s a newsworthy story every time it does appear). Most distros have ClamAV and the frontend ClamTk in their repos, but it’s primarily used to scan servers for Windows malware before it reaches its intended target. Some Windows malware can still be harmful if run with Wine/Proton, but unless you’re downloading and running a lot of Windows software from unofficial sources (which you shouldn’t have any reason to) that won’t be a risk.